Well, here be the problem. To tack the loops onto the criminally comfortable Arc'Teryx waist belt, you'll need to sew through ca. 1/2" of foam, which will require an industrial sewing machine. But even if you do have access to such an animal, sewing through the waist belt is going to compress the hell out of the foam where you stitch it, which may do funny things to the fit of the belt. Perhaps if you tack them on up at the top edge of the hip belt near the seam it wouldn't be too bad, however.
Or, if you don't have access to an industrial machine, you could rig some removable gear loops by either buying the 'teryx ones or making your own out of cord and tubing (use sprinkler tubing, as it's much stiffer than that fish tank stuff), then sewing each end of the cord to a short strap (whatever is long enough to go around the hip belt) with a ladderlock buckle on the end. Then you could just strap the loops on, and you'd be able to move them around a little bit if need be.