I have a Gammill, love it and bought it used, which is what I'd recommend for you. You will pay alot less, and that will resolve alot of your worries about monthly payments. I believe Gammill only finances new machines, so you'd have to make financial arrangements on your own. I know some buyers got home equity loans in the past, not sure if that's an available option now, what with today's economy and how banks are loaning right now. You can call Gammill and ask them about their financing program. ALso, when looking at used machines, get the serial number and Gammill can tell you the manufacture date.
As far as other machines go, I can't tell you anything about the Handiquilter, but I didn't care for the APQS machines because the ones I tried/saw always stitched a few more stitches after stitching was "stopped". I tried an A-1 machine this past spring at a quilt show because it has a good reputation and I know many quilters consider that machine and the Gammill to be the two best machines out there, and I liked it alot. I found it to be very smooth running and very quiet, a machine I think I'd like.