It'd be easier to suggest a flying type if you showed us the rest of your team. So far we only know of Swampert...and we can't make much of a suggestion off of that. Each pokemon serves different roles which is why we need to see it. Do you need a wall? Do you need something that isn't SR weak? Ect, ect.
So basically we just need to see the rest of your team (planned sets as well, just stating a pokemon's name is no help as a good amount of pokemon have various capabilities).
Well my team is/was
Swampert the new EV one
Staraptor - Need a new flying type as its not EV trained
The rest arent EV train so Im going to re do my team with different pokemon but here they are
Infernape
Scizor
Pikachu
Lucario
So i had some balanced team that could take care of nearly everytype of pokemon.., I will keep my Staraptor but for in game but need a new team for in game and wifi as I explained so i do need a Flying / Fire / Electric...not sure about the other two type might think have a dragon.
But at mo im concentrating on a flying type
Hope this has answerd your Question.