Hi CindyG_LV,
The Las Vegas list was last updated in Jan, 2014 so I checked the list and two of the stores were now gone so I’ve deleted them and changed some of the other descriptions so it’s up to date. Thanks for letting me know that it wasn’t up to date :).
I don’t have a record of the specific mattresses that each retailer/manufacturer carries on their floor (keeping up with the specifics of all the mattresses on the showroom floors of all the retailers or manufacturers that are listed throughout the hundreds of forum lists would be a bigger job than anyone could keep up with in a constantly changing market) but I know that Ergo Bedroom would have a range of latex mattresses that you could test (including Savvy Rest which is a component latex mattress where you can choose each individual layer) and R&S mattress may also have some all latex mattresses made by Brooklyn Bedding as well (but call first to confirm this because they may only have latex hybrids).
Phoenix