I don't do a lot of quilting, at least not fancy quilting...
So far, my Bernina 830 ($400.00 a few years ago) seems to handle anything I throw at it. Anything. I am almost finished straight line quilting a queen sized quilt with it right now. It's just hard wrestling with that much fabric.
http://www.quiltingboard.com/posts/list/2480.page
For what you want to do, this machine (and a lot of other heavy duty home machines) will allow you to do straight line quilting very easily. A queen size quilt is a lot more work than a lap sized one (even for my big lap).
A couple of months ago I went to the Pacific International Quilt Show here in Santa Clara. I saw a neat looking little device that you put your machine on. It had four casters that the machine rolled around on and the quilt was suspended up at the sewing level, nicely rolled front and back. About a $150.00 if I remember correct. Just right for three or four lap quilts a year I would think. Then you could get into some fancy axed quilting there for a moderate price.
Did I buy one? Nah, I was feeling poor.
tim in san jose