Hi Gael,
I don't recall the exact website, but I do remember that I googled "make-it-yourself quilt frame" and 'like grace quilt', etc.
It cost about $75, including fabric to tack the back, batting, and front onto, springs, nuts, bolts, and heavy strapping to hold it all together. This was about 6 years ago, so it might be closer to $100 now.