One of the main reasons Communication is so important! And looking at the work of the quilter. If you tell your quilter you want large, loose quilting, not dense quilting that is what should happen. If you tell her -- do what ever you think...she will do what she enjoys doing... Possibly very dense quilting.
Any sewing machine that has a nice even straight stitch can be used for quilting. It just takes practice. Some wonderful quilters manage to quilt huge quilts on small machines.
Visit some local shops where you could possibly try out machines or take classes.