I don't use anything. If I was going to get anything, I'd use open front boots (I have some, actually), since my mare usually smashes the stadium jumps, and I want her to feel it.
If your horse usually won't touch the jump, most people go with regular 'all around' boots. SMBs should work.
If he has shoes, you might want to put some bell boots on, if you think he'll over reach and step on the back of his shoe.
I personally don't use anything on the front legs since my mare has difficulty fully bending her legs up if she has polos/boots on, and since I'd like her to snap them up better, I don't bother. If I do use polos, I keep them lower than most people (almost an inch below the knee in back).
My mare doesn't fit herself, so why bother? :) They only inhibit her movement.