Just now saw you question about Skitty. If you wanted to battle over Wifi then you would need to consider Ev training it and its Ivs but just for in game battles and completing the game you don't need to worry about all that leveling it up will be fine.
Yeah I would go on route 42 and catch one. It would probably be easier than training a mareep from a low level. Although you would probably have to train Flaafy a little bit too because it appears at levels 15-17, but thats better than a very low level Mareep.