You might want to join the homequiltingsystems group on Yahoo. They are a super great group. I have learned so many things from all of them.
One of the great things they have is a file section. In there is a comparison for many of the different long or mid arm systems. There are so many out there, that everyone that has a different one will tell you to buy that kind. You need to go to BIG shows that have many different systems displayed and play with all of them.
How much to do you have to spend on a frame and system?
Do you have any idea who you will be quilting for? Just yourself or do it for a business? How big of quilts will you be quilting? How much room do you have for a frame? Do you want computierized or not?
These are just a few questions you need to ask yourself. Please, join the group I mentioned. You do have to submit your name and some limited info for approval, but they do that to keep spammers out. Once you have joined. look into all the great info there is. There is even pictures of many different kinds of frames and systems. Be prepared to spend hours checking it all out.
The people on that group are super and they share as much as this group does.
Don't jump in and buy the first thing you see. Try as many out as possible.
Good luck in your search.