While the sport maxx is virtually the same truck except no 4wd, I would personally opt for the 4wd, but this decision depends on what you are planning on doing with the truck. If you're planning on taking your truck out in the street and playing with your friends then the sport maxx might be the way to go. If you are even remotely considering beating your truck off road then save up and get the t-maxx.
A few things you'll need to consider is:
fuel, you'll need some to run your truck, $10 - 20
Batteries, for the radio receiver 4AA and transmitter 8AA, $5 - 10
Battery with charger, for the ezstart $10 - 15
Bottom line here factor in about $30 - 70 just to get your ready to run truck actually running.
A few other accessories you also would be advised to think about getting:
Filter oil, helps keep your engine from taking in moisture into the cylinder.
After run oil, it'll sasve you from having to buy a new engine after your engine rusts.
fuel jug for filling your tank without spilling too much
fuel filter, keeps crap for getting into your carb/engine