Hi Ninjaturtle,
this is one of the reasons I tend to avoid chain stores or most mainstream outlets. The people at smaller independent manufacturers or some of the better sleep shops tend to be much more knowledgeable and experienced and focus more on educating you than “selling” you. It takes longer than 10 minutes to do good testing on a single mattress following the testing guidelines much less to decide on which mattresses to test in the first place.
If you mean the metal rails that hold the foundation then any good store will sell versions that are suitable and most of them come from the same sources (see post #10 here for some examples). If you mean the actual beds (such as a platform bed that can be used directly under a mattress) there are a few options listed in the foundation thread here but beds are more a furniture item and are not my area of specialty. Perhaps other forum members could make some suggestions though.
Phoenix