Hi NorthernComfort,
Welcome to the Mattress Forum! 
Unfortunately, you didn’t provide much information about your current mattress (overall configuration, time you’ve had it), so I can’t make any specific meaningful comments. Without knowing your current configuration and options for increasing comfort I can’t make accurate suggestions, but an 8" flippable all-latex mattress that is “firm” could certainly be something that might not have a deep enough “comfort cradle” for many individuals. If you’re looking to increase plushness, this certainly can be accomplished through additional/different ILDs of latex and doesn’t need to be done through the use of polyfoam layers as in your old mattress.
As it seems that you’ve decided to look at something different rather than staying with your current retailer, I’ll focus my comments on the information you’ve provided in that direction. And just for the sake of clarification, and I know it may sound like a bit of semantics (but it’s important to me), and for others reading through this thread, we extend commercial site membership to an exclusive group of retailers/manufacturers who must meet stringent qualifications, as opposed to “sponsors” in the traditional sense. Thanks for allowing me to make that distinction 
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[quote]We are about to exchange this mattress however am having trouble finding something they make that I like, so I went to Mattress Firm today and layed down on a Beautyrest “legend” firm. www.sleepys.com/simmons-beautyrest/legen...tress/slp118039.html
Has a bunch of layers, probably gimmicky as it seems like they have “cooling, memory, etc etc”. I will have to say it is really comfortable. I am reluctant to get it though because of the comments I have seen here regarding the mass market manufacturers and their product leaving impressions in the comfort layer after a couple of years due to inferior materials but not enough to trigger a warranty claim.[/quote]
When trying out a mattress in person you can’t feel quality or durability. That can only be accomplished through learning about the information listed here so you can compare the quality of the materials and components to the durability guidelines here to make sure there are no lower quality materials or weak links in a mattress.
Unfortunately, the major brands such as Sealy/Stearns & Foster, Simmons, and Serta all tend to use lower quality and less durable materials in their mattresses than most of their smaller competitors that will tend to soften or break down prematurely relative to the price you pay which is why I would generally suggest avoiding all of them completely (along with the major retailers that focus on them as well) regardless of how they may feel in a showroom along with any mattress where you aren’t able to find out the type and quality/durability of the materials inside it (see the guidelines here along with post #3 here and post #12 here and post #404 here).
The term" hybrid" has become so watered down within the industry as to become meaningless, so I wouldn’t focus on terminology much but instead focus on specifications and componentry. A pocketed spring mattress certainly can be a comfortable and durable product, but it would depend largely upon the quality of foams placed on top of that innerspring unit.
That combination can be quite durable and comfortable, and a polyfoam quilted layer on top isn’t necessary to achieve plushness, unless you personally prefer the feel of polyfoam. The key would be making sure that the polyfoam quilt on top was of a higher density so as to be durable (see the guidelines I linked to previously in this post).
While of course not a complete listing, a good source of some spring/latex mattress (hybrid) providers is in post #2 here, and that can be a start in your search.
As you’re going through your research again, you may wish to read the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones.
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of “comfort”, firmness, and PPP (Posture and alignment, Pressure relief, and your own Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well he will sleep), durability (how long he 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 (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
I hope all of that helps you refine your new mattress search.
Phoenix