Hi richarddb,
Beloit Mattress is one of our members and they are a factory direct manufacturer in Beloit, WI and Rockford, IL.
There would be many mattress outlets in Dallas/Ft Worth that carry some type of gel memory foam (probably the majority of outlets) but I don’t know the specific type or source of the gel foams they may use. Post #2 here has some of the better factory direct manufacturers in Dallas but you would need to check their website or call them to find out the specific details of any gel foams they used. There are many mattress manufacturers from small to large that are using some type of gel memory foam in their mattress since the success of the Serta iComfort which uses a gel material (gel particles) that is added to the memory foam so they would be widely available although it is an “emerging” category and some types of “gel foams” are better than others.
Post #26 here talks about some of the different types.
Phoenix