The latest version of the Monster Truck uses the wider suspension of the Race Runner and Baja 1000 Evo 3 models.
The Sport model has lower spec (non-adjustable piston) shocks and only one 'open' diff. The Comp spec model has front and rear 'open' diffs. I assume that as with the Comp spec Race Runner and Baja 1000, the Comp spec Monster Truck comes with a valuable spares package (wishbones, hubs, shock forks, shock shafts, diff gears, alternative shock springs).
To be honest I would check with the dealer for the actual differences on the models they are selling. It's possible the website is showing the older pre Evo Monster Truck.....
The 2009 Race Runners (
http://www.mcdeurope.de/index.php?s=3&lang=eng) have just been released and it's possible that MCD will release a similar upgraded Monster Truck with steel gears, alloy servo tray, diff mount, fuel tank supports and new shocks.
The new models (this might include the new long wheelbase all alloy Race Runner) will be displayed at the Toy Fair in Germany early next month. It's probably worth waiting before you purchase anything - you never know what else might be on show at the Toy Fair. FG will (allegedly) be displaying the Sportsline version of the 4WD Baja and Monster/Stadium Trucks.
Clive