I went through this exact issue when I started quilting. FWIW I took a week long free motion workshop with Cindy Needham and that banished my need for a BSR attachment. In class I noticed everyone had a Juki, which at the time was one of the few machines that had a roomy harp space.
Free motion quilting takes a lot of practice (it took me a long time to be a skilled piecer, it took a while to build the free motion skills, too), but you quickly, very quickly, outgrow a need for a stitch regulator, IMHO.