I quilt in the ditch for most of my quilts first, then make the binding like you are mentionaing. to keep the back from puckering, always baste your layers first! baste the short side first every 5-6 inches, then the long side every 5-6 inches then baste all the way around the outside of the quilt. It's not easy and it works best if you have a space on the floor to lay it all out and do this. In the long run, it is worth it..no puckering on the back no matter how you quilt it. and very easy to pull out when you are done quilting and have the binding done.
I learned the technique last year, to make some table runners for Christmas. First quilting, then I cut the excess batting, I checked the size of the fabric of the backup that is equal on all four edges, built four perfect corners and finally brought everything to the front and sew around.
I've always seen it/done it quilt first, then bind...doesn't mean it's the right way, just means it's the way I've always done it/seen it done. I'm interested to see what others have to say!