Good web as well as pen and paper resource

[proditor]

http://www.dp9.com

They do a tactical wargame called "Gear Krieg" which posits a Christie designed suspension for Mecha...in the 1930's.  

They also have a nice selection of whiffer planes in their companin book "Luft Kreig" where one of the main interceptors in the US arsenal is the P-55 Ascender and the plane that won the Battle of Britain was the Gloster Pioneer!

The Luft Kreif companion has a ton of half overhead shots and some interesting custom designed planes.  I'm planning on building a F-5F5 Twincat when I get the time.  

[rallymodeller]

And Dream Pod 9's out of Montreal! Go Canada!

Been a big fan of DP9's stuff for many a year now. Looking at my bookshelf I see their Heavy Gear RPG, the Jovian Chronicles supplements for Mekton and a few issues of Mecha Press.

IIRC, the illustrations for Gear and Luft Kreig were done by Marc Alexandre Vezina, a really talented artist.