I found that machine quilting standing up is much easier on my neck and shoulders. I highly recommend trying it! My cutting table is fairly high, so I put my machine on that to machine quilt.
Here's my plan if my dh and I ever get time together to work on it.
I'd buy a table from Ikea (inexpensive with a wood top, and good-looking) and have my husband cut a hole for my sewing machine -- probably somewhere near the right of the table so quilt would be supported on the left. The cutout would be dropped down and fastened to the table with metal pieces and bolts; the tricky part would be getting it the exact depth so the bed of my machine is even with the table top. Some strips of formica edging would neaten up the hole edges.
This whole setup would probably be too low for machine quilting. If so, I'd raise the table to the correct height with lengths of PVC, or bricks. I'd also probably buy the largest sheet of teflon (baking or applique sheet) I can find and tape it down over the machine bed and table -- similar to the Supreme Slider.
I personally don't think a frame would be much help with a home sewing machine. The problem comes in with the harp size -- area between the needle and the right side of the machine. Large quilts take up so much of that area, you end up with very little width in which to maneuver while machine quilting.
The homequiltingsystems group at
http://groups.yahoo.com is a very active list of home quilters, and I've been learning a lot about frame quilting there. (A frame quilting setup is on my list of things to get when I win the lottery. Suppose it would help if I would actually buy lottery tickets once in awhile! :lol: ) Many of the people there have less expensive frame quilting systems. I think some of them even use home sewing machines. Some have purchased mid-size machines (larger harps), and I think it's the Wow! that is actually an old Singer cut in two and extended to make a mid-arm; some of the posters use that machine with a frame.
Oh, and I forgot to mention that some quilters find it easier to free-motion quilt on a home machine by sitting facing the left side of the machine. You know how you normally sit? If you think of your machine as a rectangle, you move your chair to the adjacent side on the left. Place ironing boards to the left and right to help support your quilt. The huge advantage of this setup is that you are not limited by harp size. You can be quilting down the middle of a queen-size quilt and the right side of the quilt will be as free-hanging as the left instead of rolled up or scrunched up inside the harp area. (Edit: Just realized you are still limited by harp size in terms of the bottom and top of the quilt!) I wasn't able to easily adjust to this setup but, before making the table described above, I might try practicing to see if I could get used to it. If I could, I'd place the hole in the table in the middle of the table and turn it for machine placement. That way I could quilt standing up and not have the harp limitation.