Hi Rhizzlebop,
I’m glad you found us before you pulled the trigger 
While I realize that some of the major brand mattresses can be comfortable in a showroom … the quality of the materials they use in many cases means that their comfort and/or support won’t last and even their better quality mattresses are not good value compared to mattresses made by many smaller manufacturers.
Post #1 here and the information it links to may be also be very helpful.
The local manufacturers and some of the other better options or possibilities in the Columbia and Charleston area are listed in post #2 here and post #2 here has a list centered around Greenville (with some overlap).
Phoenix