I don't think you can go wrong at all with the Hellcat, Mustang or Lightning. Regardless if it's the three-toned camo of the early Hellcats or the overall dark sea blue that they wore, I think you'd have a fairly easy time handbrushing those. I wouldn't hesitate for a minute to pick up an F6F.
For the Mustang, I think you'd be better off doing one up with it's Olive Drab over Neutral Grey scheme. Same with the Lightning. If you're going to do a natural metal finish, I don't think handbrushing it would look all that great. Instead, if I wanted to keep it simple, I'd pick up a can of Testors or Tamiya silver.
Testors has an vast array of metalic paints in aerosol form. The only unfortunate part is that they're a bit fragile in nature. In other words, you can't mask over them lest you pull up the paint when you remove the tape. You can't handle the plane much either or else the oils on your fingers will remove the paint or, at the very least, leave fingerprints on them. The Testors paints do look nice but you really have to plan ahead when using them and perhaps handle the plane with an clean old T-shirt to avoid the skin-to-paint contact.
The Tamiya silver (AS-12) in the spray can is a bit more robust. I've used it a couple of times and it worked well for me.
I hope that helps!