I have a HandiQuilter Avante (18"). I second what PaperPrincess said - your room is *not* big enough for a 10 foot table. You need to be looking at an 8' option. My Avante has that option - I can set my table up at 8 feet (it's 3 4-foot sections). With that table, you'll be able to quilt something about 72" wide at most (you lose about a foot at each end of the table for machine space, and backing space, etc. I can put 120" on my 144" table). You'll still want the table pushed against one wall. Even if you never quilt from the back (pantographs), you still need access to it for changing thread, loading quilts, reaching the power cords/power switch, etc.
Handiquilter is definitely a good brand, I really like my Avante. I'm with you that I'd avoid the Bernina. For me, one of the main reasons is that the tension is electronic, rather than a dial on the side of the machine. And it doesn't remember your settings (tension, stitch length) from one session to another.
If you are planning to sit for most of your quilting, you might find even 20" is too wide to reach. I cannot see the angle well enough to do accurate ruler work at the far side of the quilt, from a sitting position (and standing to do ruler work is hell on my back). A saddle stool is great for most free motion (and saves my back), but it does limit your reach, so again, you might not be able to take advantage of the full 20" - consider perhaps smaller if budget is a concern. Taking a class is a good idea. If at all possible, see if you can try a stool while you're there (or try one at a dealer).
Also important to consider, if you are comparing across brands, is actual quilting space, rather than throat size. For example, my APQS (26") is 8" wider in throat than my Avante. But only gives me an extra 4" quilting space. So I don't think it compares favorably to a 26" Handiquilter for usable space.