What sewing machine is recommended for quilting?
You could use just about any regular sewing machine for quilting. You can even use an old black Singer featherweight from the 1930s. All they can do is a straight stitch. (But they do a really great straight stitch!)
For quilting purposes, you need a relatively powerful machine (for sewing over thick seam allowances), reliable and uncomplicated that sews a good straight stitch.
My favorite machines for quilting are Bernina's, (particularly the 730e, which has a reputation as the best all-purpose machine available), other good options are the Baby Lock Esante, Brother Serger, Pfaff Performance 2054 and Juki TL 2010Q.