Are you any good with a needle and thread? I just choose some gloves which fit the bill in every other respect apart from fold back finger and thumb. It's fairly straightforward (~30 mins work) to adapt them, I simply make a lateral cut across the inside of the left index and left thumb, contain the ragged edges with a strip of ribbon or hemming material, and finish them off with a patches of velcro on the respective nails and knuckles. The cuts will compromise the waterproofness, but no glove is truly waterproof and also usable!