Hi Stardustgirl,
I think you may have dodged a bullet by not purchasing the Peabody Dream Bed. You can read a little more about hotel mattresses in post #3 here and the posts it links to but hotel mattresses made by major manufacturers are typically not even in the same quality/value range as similar consumer versions of the mattresses made by the same manufacturer and I would avoid their consumer mattresses as well since they tend to use lower quality and less durable materials than many of their smaller competitors.
The first place I would start your mattress research is the mattress shopping tutorial here which has all the basic information, steps, and guidelines that can help you make the best possible choices … and perhaps even more importantly know how and why to avoid the worst ones.
FWIW … many people who are changing from a waterbed like the “feel” of latex mattresses since in the right design and firmness level they can be a great choice in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and they are also more “lively” than other types of foam which many people who are switching from a waterbed seem to like. Latex in general is also the most durable of all the different types of foam (polyfoam, memory foam, and latex foam). Of course this is only a preference and not a “better worse” choice and others may not have the same preference so your own testing and experience is always the best way to know the types of mattresses you tend to prefer.
The tutorial includes a link to a list of many of the better online manufacturers and retailers I’m aware of that sell a wide range of latex and latex hybrid mattresses and if you let me know your city or zip code I’d also be happy to let you know of any of the better options or possibilities I’m aware of that are local to you.
I’m looking forward to finding out what you end up deciding and of course any feedback or questions you may have along the way.
Phoenix