i think that its cool that youre trying to keep it original looking....ive only ever heard good things about the mitsu built challengers.

to fix that window seal issue, i know that there are companies who specialize in making replacement window rubbers, and as for the door, your best bet is to remove the inner door panel, and see how bad the inside of the door is...if its not too bad, it shouldnt be a big fix from a body shop.