I am going to be buying new batteries for both my plane and my tx. I've been using the batteries that came with the model when I bought it used and i'm starting to lose faith in them. My question is(I havent really learned that much about batteries yet) Which kind and size would be the best to put in a tower trainer 40. and where can I get a new rechargable pack for an airtronics vg400 tx?

thanks