Out of 7 I've had mud shot with all but one evolve!
Ice Punch gives a bit of a surprise to attacking grasses and dragonites, but probably doesn't stop you getting killed.
Submission probably does more damage to a wider range of species and is slightly confusing to dodge.
Hydro pump is easily dodgeable for a lot of players, but will still inflict some damage even if dodged. Will seriously damage anyone who doesn't.
I'd be tempted by no1 , unless candy and dust really aren't a concern, in which case go for no3 for the marginally higher gym position (depending on local gyms you'll probably want to take him a little beyond lv30 to stop him being the bottom defender).