For the storyline i'll have a lame team, but Chikorita is my starter anyways. It's my second favorite starter of all of them, and I really want to see how it can work in 4th gen, yet in his "home" region.
Anyways, my team would be something like (at the league, and a bit past the league): Meganium, Espeon, Togetic(Togekiss?), Red Gyarados, The last evo of Mareep and...who knows...Gengar/Houndoom/Crobat or any banalic thing.
Oh and edit, i'll probably take Pidgeot if we won't get Togekiss before the National dex.