Hi Andrew,
I've done hangar-9 Spitfire & P-40. The Spitty is a great candidate for a battery hatch. Here is a link to my hatch thread;
http://www.rcgroups.com/forums/showt...ight=rickavery
The P-40 not such a good candidate as the space & bulkheads aren't as convienent for such. Both are wonderful fliers with power 60s on 6s. The Spitty has split flaps and lands like a feather. For fear of tip stalling, I land the P-40 a bit fast and let her roll out. The P-40 ended up almost 2lbs. lighter than the Spit although the dimensions are are very similar?? The flaps & servo on the Spit add some, not sure where the rest of it comes from. With identical power systems, the P-40 performs better, 2lbs really shows up. Unfortunately, hangar-9 has discontinued the P-40. I found mine on fee-bay. I think I'd like to do a skyraider as above. Good luck in your search.
Rick