Send me your address and I'll send out some grip leather for you.
I have deer, elk, cow, moose, goat, calf and a few others I'm forgetting.
For a wrapped grip like on the old Bears, veggie tanned calf or goat work great. For a laced grip, the garment tanned deer and cow, and a pig split work excellent. The elk and moose is usually pretty thick for a grip.
For lacing I've used artificial sinew, any of the string material (B50 is cheap) and leather lacing.
-Jeremy