About the weight issues, The flies with a thread wrap head have a .025 wire wrap, and the wire abdomen weighs quite a bit too. It isn't the normal ultra wire, just some 28ga wire I found at a hobby shop. It's a little harder to work with, but much heavier than ultra wire. I'll give your 2nd bead idea a shot if I have some smaller ones that can make it through the bend in the hook.
I believe I'll fish most of them with some split shot in faster water, but they should do ok in slower water and pools.
I'd love to see some more stonefly ideas here.