As FelineFanatic mentioned ... test driving long-arms is an absolute must. They're like automobiles, each of them has a different "feel" to it. You don't want to get a machine and find out later there is some weird quirk about it that you absolutely hate - and suck all the joy out of using it.
If you were willing/able to travel then your best bet would be to get to a large quilt show in the near future. Most of the major machine manufacturers have their long arm setups on hand for folks to test drive - and make deals. The booth is typically manned by a local (to the show) store.
Unfortunately, most of the major quilt shows have happened already, at least until the fall. Not sure of any that happen in the summer.
It's a big investment, if I were in your shoes, I would wait until I could attend a large quilt show to test drive multiple machines.
good luck!!