The R hop needs a flat nub, so you'll either have to modify the hop arm in the Krytac hop up, or modify an aftermarket hop if you possibly want to put the gun back to stock.
The Krytac hop is pretty damn good lifting up to 0.3g BBs, so the R hop isn't really going to gain anything unless you're shooting heavier, and there's nothing wrong with the stock barrel either.
An M110 spring is going to be shooting around 370+fps,so check you're not going over your field limits.