RE: TRex Differences
I'd get the V3, with a Futaba GY401 gyro, a Futaba 7CH or 9CH or JR8103 or JR9303 radio for it. Also I suggest you get a kit, so you'll know how to take it apart and put it back together after you crash it. The JR241 servos or the Hitec HS56 would be my choice. Also a Thunder Power 3S 2100mah li-po battery. Align stuff is probably okay for the rest.
The JR610UL receiver comes with a crystal so if you go that route you won't need a seperate crystal and it's a great receiver.