Nice buggy, you got a real steal on it, I converted a lightning 2 pro (bought new for £195) and have had a lot of fun with it, the only times its broken or bent anything is when its been going flat out and hit something concrete, it laughs off cartwheels, car tyres and fence posts.
Knowing the Lightning 2 pro as I do, I can say that that isn't one, its either an L1P or an L2RTR there are some subtle differences that distinguish mine from yours, my L2P has a lay down steering servo, it has thicker and contoured shock towers front and rear, its chassis braces are solid 7075 rather than tie rods, its chassis, front hubs and steering link bar are all 7075 and anodised purple, shocks are different too but that may be an aftermarket modification. Whichever version it is though for that price its a great deal so I wouldn't complain in case the seller changes his mind, and there all good buggys.
here's a couple of pictures of my L2P for comparison

naked during the build

and as it is now, I had to add the 40mm fan on the MM and the 30mm fans on the motor when I went from 12cells to 4s
I was trying to find somewhere that had those purple heatsinks (as its mainly a purple buggy) in stock when I was putting mine together but no one had any so I went with a black RCM heatsink/clamp, now I am going to be moving away from the feigao soon I won't need the clamp and I am looking for them again, where did you get them from?
I am going to disagree with the others and say 3s will do you fine, while 4s will be faster, you would then have to upgrade your motor, I run 4s with an 8XL (bigger and lower KV) and it still gets very hot with the heatsink and 2 fans on it with a 14t pinion on kyosho 46t spur and with small diameter on-road tyres, so I say stick with 3s untill you get bored with the performance and want more speed then go to 4s and a better quality motor like neu, lehner, pletenberg, mega, kontronic.