1. RTR - this is great if youre starting from scratch. it includes a radio, esc, and motor. youll have to buy a battery and charger.
2. racer - im not sure if this is still available. it is basically an unassembled RTR and youll have to buy the electronics separately.
3. team - this includes some hopups that doesnt come with the racer kit. titanium turnbuckles, aluminum shocks and CVD bones, teflon sealed bearings. but this doesnt include a body.
4. factory team - this is fully loaded with almost all the available TC3 hopups. full graphite kit, threaded shocks, aluminum screw kit, etc. it doesnt include a body and wheels/tires.
if you plan to race from the start, go for the factory team. this will be cheaper than buying all the hopups separately. the racer and team kits are also race ready if you already have racing gear (esc, motors, batt, charger, etc.) but for the price, i think the best value would be the factory team. click on the TC3 thread, you'll find lots of info there.