Since you are inside the EU, I will say that the best dealer is Hobbythek (http://www.rc-car-online.de)

You can use the same servos as for the FG Marder. I am running mine with a Hitec 645MG for throttle/brake and a pair of cheap Jamara 21kg/cm Jumbo servos for steering.

Acocrding to the FG Catalog 3, The Leopard Race does not come with the Gear wheel protector as standard.

There is no stabilizers included.

If you want the FG 4wd upgrade, then I guess that it will be a long time comming for the Leopard Race.

Since the Leopard Race is a bit longer, and also has the engine tilted slightly forward, it has more weight on the front, and a lower center of gravity than the FG Marder.
This translats to a better handling, and being less prone to make wheelies, but a friend with a Marder Race outruns me every time, as I am a BAD driver.