Sew Classic carries a variety of different walking feet for many different types of machines. So you may want to double check which one you have.
You'll have to gauge the pressure as every machine is different. I typically find that midway is fine, but I usually need to lower the top tension a smidge and lengthen the stitch length depending on the batting and fabrics used. Really, every situation is different depending on the machine and quilt sandwich you're using. Do a sample first.