If you're buying your air filter from the local parts store, take the old one with you to compare. If ordering online, I'd go with the one you already know fits. However, make sure that it actually does fit properly and seals any air gaps between the filter and the air cleaner housing inside when the top is fastened down. 

On the ATF fluid, I'd probably go with type F simply because that's what you'll have on hand and what it's probably been fed all it's life... but I really don't think it makes much difference.