The both cars are good. I'd look more towards the Kyosho myself. Better pars quallity. There were a few versions of the 777 (sp-1, sp-2 and WC, I think) The parts for the Kyosho are a lot more expensive but the quality is as good as it gets. The engine is nice but, you really don't know what condition it's in. Not worth more than $100 unless you really trust the person selling it.

The Jammin is also a good car. Check the drive train parts for wear. They used a soft steel that wore pretty fast. If it looks tight, it may be the better deal.

each car has it's weaknesses and benifits. Parts support is something you need to check into. If the car is popular at the track it helps also for parts and set-ups.

You want a steering servo with 100 oz torque minimum. 150 is really what you want if you can afford it. Throttle servo should be close to 100 oz also.