Hi! I'm new here too - but welcome :)
As far as the machine goes - I'm not a Bernina junkie, so I would say, go with the one you can afford and does what you need it to. For quilting a larger throat comes in handy, if that's possible on those machines. Most quilters only use the straight stitch, but a zig-zag comes in handy at times too!
Good luck figuring it out ~
Amy