Hey les_garten,
Welcome back to the Mattress Forum! Thanks for your question. Thanks too @Sweet Dreams/ Bill for your excellent insights, you are a great TMU consumer advocate 
.
[quote]I am 5’11" and weigh 240. I sleep on my side. I am on an older Select Comfort Pillow Top now. I prefer it somewhat firm. I sometimes have my arm go asleep at night and force me to switch sides. Also happens with hip pain as well.
I am thinking of a Sleep on Latex Mattress that is 6"/2" medium or firm
Then a topper made of 2" Medium Dunlop and 1" Soft Dunlop from SOL as well
Total of about 12" with the covers
These will be (2) Twin XLs on my Select Comfort base
Here’s my questions:
- Should I get the Firm or Medium mattress?
- Does this setup sound ok?[/quote]
Shopping for a new mattress is a personal journey based on our sleeping history and preferences, hopefully you’ve already 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.
What’s key is to find a mattress company that will work with you, not only to answer your questions but also to help find a bed for you that will last many years. Here at TMU, our trusted member retailers/ manufacturers carry a wide variety of choices, including dunlop latex mattresses which you have indicated interest in. Hope this helps with your research, let us know how things go.
Thanks,
Sensei