Hi Toshi,
The series I was talking about was the Academy series of P-51 kits.
They make an early Allison engined P-51 that came with some extras - A recon camera behind the pilots seat and a jeep.
They also have individual kits for the B (old crow), C (Tuskeegee red tail), & D versions. I've built all but the D version and I would recommend them all - they share alot of the same parts.
With the P-40 they have the E kit, and another P-40 kit with a longer fuselage for the M & N versions. All of these kits are newer releases with excellent surface detail and fit.
The Corsair is really nice - that is also a (kindof) newer kit.
The SB2C-4 Helldiver is a GREAT kit. I'd say probably the best 1/72 kit I've ever built.
The Wildcat and the P40-B are older kits. I've built the wildcat. I wouldn't recommend it - go for the new Airfix Wildcat. I haven't built the airfix kit yet, but it looks incredible in the box and reviews have been really good. It has a wingfold option and is a great price for a kit of this high quality.
I remember hearing that the Academy P-40B wasn't that great. It is very old.
Hope that helps.
Chris