Critique my HG Story Team

[Jamiam]

I'm planning to go through the game with these pokemon. Tell me how i can replace, fix, pr power up my team.

Cyndaquil->Quilava->Typhlosion.
Bellsprout->Weepinbell->Victreebel
Polywag->Polywhirl->Polywrath
Gastly->Haunter->Gengar
Abra->Kadrabra->Alakazam

Polywrath, Gengar, And Alakazam are the one's i'll be trading to Diamond and then back to acquire their max evolutions.

The main problem with it is my 6th. Who should it be? I was thinking piloswine...

 

[Ho-Oh]

Well you don't really have anything to really hurt psychic types. ;x So maybe a dark type? Since psychic hurts Poliwrath and Gengar - and does neutral to the others, other than Alakazam. Plus you have Gengar to cover that dark weakness. You could always give Alakazam Shadow Ball, but yeah, a full-on dark type could be useful, like maybe Weavile, since it'd cover ice as you want, too.

Either way, we really need the attacks you're considering using + items/abilities/so on (though not as important in-game, however the attacks are essential) otherwise we can't really rate much.