The hogue grip works great for larger hands, it's a good bit thicker than a stock AR15 grip it's overmolded in rubber (very tactile) and has nice palm swells. If you want even thicker, the SPR sniper grip is nice, it's molded out of a fiber reinforced nylon not quite as tactile "feeling" but it's way wider, it is pretty much for right handers only, as it has a molded in thumb rest on the grip.
SPR type
My Hogue