Hi Cajen9669,
Welcome to the site … and I’m glad you found us 
There is more about the most important parts of the “value” of a mattress purchase in post #13 here which which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists (based on all the parts of your personal value equation that are most important to you).
In terms of suitability …
The first suggestion I would have is to confirm is that the Tempurpedic Supreme Breeze really is the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) hopefully using the testing guidelines in the tutorial post and with both of you on the mattress. This would be especially important with your bad back in combination with your higher weight because a mattress that is too soft for you certainly won’t do your back any favors.
The Ultimate Dreams Supreme Gel is designed to be closely comparable to the firmness of the Tempurpedic Cloud Supreme (which in turn is similar to the Tempurpedic Cloud Supreme Breeze) and the Select Foam Cirrus Supreme is designed to be closely comparable to the Tempurpedic Cloud Supreme Breeze so if you are confident that the Supreme Breeze really is a good match for both of you then both of these would certainly be “in the range” that would be suitable for you. Loom & Leaf compares their mattress to the Cloud Luxe Breeze on their website but I don’t know if they are comparing them based on firmness and “feel” or based on the quality of the materials they are using but if it’s based on firmness and feel then it would be a little softer than the Supreme Breeze which in turn could be more risky in terms of maintaining good alignment on the mattress over the course of the night.
I would also make sure you talk to each of your finalists on the phone because when you can’t test a mattress in person before a purchase then most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart who can help “talk you through” the specifics of their mattresses and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked that they are familiar with, any special considerations you may have, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs or firmness options to different body types, sleeping positions, and preferences or even to other mattresses that they are familiar with than anyone else.
In terms of quality and durability …
As you can see in the quality and durability guidelines here … you are on the edge of the weight range where I would be cautious with the use of 4 lb memory foam which may soften or break down faster than higher density memory foams.
The Ultimate Dreams Supreme Gel uses 1.5" of softer 4 lb memory foam on top of 2.5" of firmer memory foam on top of an 8" 1.8 lb polyfoam support core so with 4" of 4 lb memory foam there would be a higher risk of foam softening which could reduce the useful life of a mattress relative to your weight range.
The Loom & Leaf uses a “belly band” of soft solid gel which in theory could help with alignment by providing some additional support and “holding up” the heavier parts of your body (hips and pelvis) but the top layer is 2" of convoluted 4 lb memory foam and convoluted foam would be less durable than solid layers of the same density foam. The 2.5" of 5.3 lb memory foam underneath this would be suitable for your body weight but there is also a 2" transition layer of polyfoam underneath this which is most likely 1.5 lb density and with your higher weight you would compress this layer more than someone who was lighter so it would also be lower density than I would be comfortable with in your weight range.
The Select Foam Cirrus Supreme uses 2" of 4 lb gel memory foam (non convoluted) on top of 2" of 5.3 lb gel memory foam on top of a base layer that would be more than 2 lb density so it has the least amount of lower density memory foam and a higher density base layer so it would likely be the most durable of your three choices and would be similar in terms of durability to the Tempurpedic Cloud Supreme Breeze.
In terms of value …
“Value” depends on all the objective, subjective, and intangible criteria that are part of a mattress purchase including the suitability of a mattress, the durability of a mattress, and all the other parts of your personal value equation that are most important to you including of course the price and the options you have after a purchase to exchange or return the mattress and the cost involved just in case your choice doesn’t turn out as well as you hoped for.
In terms of price … the Dreamfoam is by far the lowest price. They are $549 queen or $749 king less 10% if you order from the Dreamfoam site and you would also receive a free pillow bonus for your membership here. The significantly lower price may be enough to offset the potential lower durability of thicker layers of 4 lb memory foam. If you order from the Dreamfoam site they have a 45 day trial period and there is a $99 cost to return the mattress for a refund if it doesn’t turn out to be a suitable choice in terms of PPP.
The Loom & Leaf is $999 queen or $1399 king which is almost twice the cost of the Dreamfoam. It has the potential advantage of the zoned construction but there is also some risk of durability issues relative to your weight range because of the quality/density of the foam layers they are using. They have a 100 day trial period and they don’t return the shipping cost if your mattress doesn’t turn out to be a suitable choice in terms of PPP but this would likely also be under $100.
Select Foam Cirrus Supreme is $1399 queen or $1699 king less the 5% discount for your membership here. They are the most costly of your three choices but they also use the highest quality materials and would likely also be the most durable choice out of the three. They have a 90 day trial period and there is no cost involved in returning the mattress for a refund if it doesn’t turn out to be as suitable choice in terms of PPP.
There is also more about the different ways that one mattress can approximate or “match” another one in post #9 here. Select Foam also specifically designs their mattresses to be close approximations to the Tempurpedic Mattresses in terms of feel and firmness levels (although this can also be somewhat subjective) based partly on side by side comparisons in their store in Tampa and they use the same or better quality/density materials as Tempurpedic as well. As you mentioned though … a few of their customers have experienced delays and customer service issues after their purchase including with refunds and I would certainly take this and the frustration that can go with it into account and factor it in as part of your decision about who you are most comfortable dealing with (see post #4 here).
Hopefully this will help you with making your final choice between them
Phoenix
NOTE ADDED: Because of ongoing customer service issues and delays Select Foam’s membership has been terminated and I would read the warning here before considering them.