XD - I'm not an ubers person, so I really can't give awesome advice.
Scarfed Skymin works more for revenge kills imo. Predicting with it can cost you a pokemon pretty easily with all the crazy things running around.
Debate on Rayquaza and Salamence just points to ice being a better option though, haha. Rock seems to only really give it the edge of Ho-Oh. It would be a different set then any other Shaymin out there, but I suppose in ubers ice is the better option and fire is pretty solid in OU play. Shaymin main attraction is always Seed Flare though, haha.