I would like to ask for the Me-410. Depending on the model added, guns available would range in size from 13mm all the way upto 50mm. It would also provide us with at more survivable, more flexible ground-attack fighter for the Luftwaffe. Something that might be able to compete with the tyhpoon, and P-47.
I would also like to ask for the Panzer III Ausf. J1 and Ausf L. The J had 50mm of armor, while the L had 70. Both used the same cannon (an automatic version was used on the Me-410). It would give us an EW tank to give the T-34 a run for its money, and the L would give us a tank that could be quite respectable in the LW arena under certian conditions.
The SdKfz 234/2 "Puma" and 234/4 would also be very nice additions. It was an german 8-rad armored car, the 234/2 using the same 50mm gun as the Panzer III and Me-410, and the 234/4 used a Pak 40 75mm gun. A bit slower than the M8, but with heavier firepower and armor. These would be very usefull for town defense and ambush situations.
Along with these, I would like to request HVAP rounds for the 50mm armed vehicles. It would increase peneration to 134mm at point blank range, but standard AP rounds would out-preform once past 700yd or so.
All of these use either the same gun, or a gun already existing in the game, which would simplify addition.