http://www.skytrex.com I think I will get here saw this link on a thread here ht eother day seems pratty good and it has pretty much every vehicle in WW2.
Also in regards to the arty that speciall attack would be like this.
At the begining of combat if there are 2 or more SPA’s in combat they fire each one shot and hit on a roll of 1, units hit by this cannot fire back.
But maybe this rule is to overpowered it seemed cool on paper but I dunno hehe, just seems to much and I wanted to keep the SPA cost low.
Also I Thought up of a speciall ability for the SPG. Since it is an anti tank wep as long as it is defending you can call a specific target wich must be an armored vehicle.
Edit: Also I was thinking of adding Heay tanks only for Germany and USSR since they where the only ones who reallky used them in the war.