You may want to go over and join the homequitingsystem group on Yahoo. I've belonged for many years now and they have in their files, a checklist on what to look for. You do need to make a wish list and decide what you need and what you don't need. The list of stuff they have now is endless. One more factor - just how deep are your pockets? Take your time and do go to shows and test drive them. Take your wish list and go and play.
I too, just got back from Paducah quilt show, there were so many frames and longarms, it was mind blowing. I have a homestretched machine on a homemade frame. I know I won't be buying one of those beauties, so I walked right by them. I would love to play on one, but then, I would want one - and that isn't going to happen. I do get many quilts done on my system.
Good luck on your search.