I tow with a 97 Four Winds 31' C-class. Its on an E-SuperDuty chassis with air-assist bags in the rear. and a full frame extension to the bumper. Not the same as your A-class, but the powertrain would be the same. I wouldn't want to try to tow 10k with it! I just have an open trailer, roughly 5k lbs with my car on it and it tows that pretty well.

To be honest, I think 10k may just be too much for a triton V10 thats already worked pretty hard pulling the chassis alone. the '01 & newer Ford has the 5-spd. transmission, and I've heard that helps alot with towing because the V10 likes to rev. A toad may help the chassis with the weight, but I'm skeptical about the long term ability of that powerteam to do the job you're asking it to. I think the job you're looking at really requires a FRED or a D-pusher, if you want it to last at all.