I would like to request the SdKfz 164, also kown as the Nashorn.
Armor:
                                  thickness/slope  
                          front           side          rear
gun shield          15mm/30°
superstructure    15mm/70°    10mm/15°  10mm/10°
hull                   30mm/12°    20mm/0°    20mm/21°
Armament: KwK 43 L'71, 40 rounds of ammunition
Speed: 42km/hr (26.71mph)
This would provide us with a cheaply perked or free vehicle able of penetrating the frontal armor of the Tiger II at combat ranges. Easily destroyed or damaged by any cannon armed vehicle, even the SdKfz 251 could turret it with the 7.92mm mg's. This would provide us a vehicle with a superb gun, and good mobility, balanced by very weak armor.