Hi bvanderheyden88,
Out of the companies you have mentioned … the only one I would recommend is Rocky Mountain Mattress because they are members of this site (which are the only companies I officially recommend).
The Pomarelle is certainly good value but I would talk with Rocky Mountain about whether it may be a suitable for you. You would need to tell them your specs including your weight, your normal sleeping positions, and your firmness and “feel” preferences so they could tell you how well the mattress “matched” your needs and preferences. It only has 2" of memory foam and a 5" base layer so much of the “feel” and performance of this mattress would come from the base layer. The good news is that with only 2" of memory foam … foam softening wouldn’t be as big an issue as it would be with your weight if you had a thicker layer of 4 lb memory foam.
You may also want to talk with them about The Foamex 4 lb 8" mattress here which is a little more expensive gives you the ability to choose the firmness of your base layers (for best support) and has a zip cover so they can be re-arranged if necessary.
Some other possibilities include …
Ultimate Dreams 10" Gel Memory Foam Mattress They are also a member here and have some great quality and value mattresses. There are no refunds or exchanges though so make sure you talk with them so they can tell you how the mattress may feel and perform for you.
http://fullhousefurniture.com/store//easyrest.html They have some excellent prices on Easy Rest mattresses and they can be ordered online but you would be on your own in terms of how suitable any particular mattress may be (they will simply send you what you order but don’t provide guidelines about which mattress may be most suitable for you and there are no refunds or exchanges).
There are also some other possibilities listed in post #12 here as well that sell queen size memory foam mattresses for under $600 that would also be worth talking to on the phone. Make sure though that you know the details of the layers of any mattress you are considering so you can make “apples to apples” comparisons with other mattresses.
There are too many variables, different types of material and layering, and individual needs and preferences involved for me to recommend specific mattresses or even specific layering combinations for people … especially without reference points of mattresses with known layers that they have tested in person. My role is to help the forum members “connect” with better sources and give them a better sense of the tradeoffs involved in different mattress types and materials and then to “get out of the way” so they can talk to the better manufacturers or retailers (who are the experts on their own mattresses) and make a choice based on their own “value equation” (see post #46 here) rather than mine. The manufacturers themselves have much more detailed knowledge of their specific mattresses and have a database they can use as a reference point to help their customers decide on which may be the most suitable option that they offer based on the “averages” of other people.
Phoenix