I haven't tried Hends or Veevus quills, but it sounds promising. I use Veevus thread more and more these days. I have been using porcupine quills/guard hairs for some mayfly bodies. We encountered a great light cahill hatch on a new stream this spring, and I had some snowshoe winged cahills I'd bought from Penns Creek Anglers, my favorite shop on the creek. (I buy Bruce's flies primarily to see new patterns and to support the shop.) The fish demolished them in time, so I've been tying more, some with white deerhair, some with snowshoe comparadun style wings. I've used a variety of body materials, including snowshoe underfur, and cream white porcupine quills. Allen Landheer, a local tyer uses porcupine for mayfly abdomens, and highly recommends the quills. He coats the abdomens with thin Solarez, applied very sparingly, so I've done that. The bodies look very realistic, well segmented--and according to Al, the quills are tough and buoyant. I've tied some rusty spinners with them, and I'm going to tie some sulphurs with dyed quills this winter, and perhaps some olives. After trying my typical emergers, etc. I used a quill bodied sulphur comparadun on the East Branch of the Delaware a few years back, and it seemed the only thing fish would take--though I'm well aware of what scientists call superstitious behavior. But the experience sold me. It's been hard to find good quills; Al takes them from road killed porcupines, but I haven't tried that . . . yet. I have two packs I bought, and I've dyed up about half of them in yellow, orange, rusty brown, and olive, keeping some natural white, but my source seems to have dried up.
"He spread them a yard and a half. 'And every one that got away is this big.'"
--Fred Chappell