Buy a prindle or hobie (get an 18', you will regret t if you don't). Parts are easier to find (and you can find used sails, tramps etc) and there are large owners groups who will be able to give you help and advice on any problems you may encounter.
I have a g-cat 5.7 (18.5') and 4 adults is quite a full load and that includes the fact that I have a front trampoline . Plus 4 people don't move around so quickly so you will most likely all wind up in the water if there is any significant wind.
Be patient and you will likely find something within easier driving distance than Tennessee, think about it you are talking about $500+ transportation costs to drive down and get it, plus a week of your life. Not to figure in any problems you have with trailering it home (tires, bearings...whatever).
Good Luck
ps I live in Denver and there are always Cats for sale in the denver post
Since the sailing season is over