Your best bet as others have mentioned is to try out as many quilt systems as possible. I went to a quilt show where there will be all sorts of systems and folks to talk to about each system. I started off small just to see if I'd like to quilt. Grace Pro frame 10ft with a 9" throat Viking MegaQuilter. Right off I realized 9" doesn't give you much but then I added a robotic system plus they also had an add-on that would give you up to 18". The add-on didn't work well so I moved up to a stretched Juki which then gave me the 18". FInally decided to go all the way moving up to a 26" with robotics on a 12ft frame. Have changed robotic systems since then but I'm happy with what I've got now. Again, I didn't know if I'd even like to quilt so didn't want to put too much money into it until I found out. As it is, I haven't touched my system in almost 9 months now as my mojo decided to take a vacation it seems.
First find out if you really like to quilt, then make a list of the options you might want on it or can add to it as you go along, then test out all of them you can find. Also check to see what customer service they offer as that's an important part of owning your own system. If you have no customer service support, a broken machine is just a door stop to you.