I don't know if you have any reason to go to Salt Lake City, UT, but there is a home machine quilting expo there this spring, which will more than likely have many machine vendors, including longarms. Here's a link to the page:
http://www.hmqs.org/
Another machine quilting show in Witchita, KS
http://www.mqsshow.org/
Several of the machine manufacturers will list local dealers.
I would try and at least find the machine you're considering before buying. It's quite an investment. Make sure you like it.