Problem with the bowfishing point is that it'll really mess up the meat, hide, etc and that's just no bueno. (Trust me I made that mistake on a chukar; he ended up as food for my redtail) Personally for homemade small game heads I like to use .38 special brass that's been half filled with melted lead (I know not very environmentally friendly) then glued onto the shaft; they usually do a fair amount of percussive damage and will drop a rabbit 8 times out of 10. Another idea I've been messing with is using a bodkin style tip with a mushroom shaped tip as apposed to a sharp needle, they're iffy so far (Don't fly too well and they're really heavy)
If you want to spend some money you could always use glue on Judo blunts, or use rubber blunt tips with a spiraled wire to catch brush. I'll try to post picks of what I'm talking about