Im still kind of a newbie to this game. Whats a better choice for active, more offensive style of play? I heard Teutons are best for that at the start, but that Romans get better at it as the game goes on.
Romans are stronger but more expensive, means it is harder to rebuild a hammer. Teuts are often asked by alliance to lead trains, often with rams and brewery active, and start attacks relatively early on server. Romans can be allowed to build up first. If you don't have an alliance to back you up yet I would suggest to try teuton first.
Dont worry about the troop cost - it's only a difference of couple of thousand resource per hour. You should be able to keep 24/7 troops queues, no matter which tribe you choose.
Teutons can produce more attacking power per time. So if you like the smashy style of playing then you probably want to play teutons. Upkeep won't be the issue since eventually you'll be running into some defense and you lose troops.
If you however want to have a huge WW hammer and you play by yourself, then you probably want to play Romans since they have more attacking power per crop consumption.
I personally like Romans for both play styles. Nothing keeps you from building two or more hammers at time if you have enough resources to do so.