Questions are good but we kinda need to know what you plan to use it as..
Ex... Dirt or Street If you want flat out speed the Traxxas VXL system with 11.1V lipo is a screamer. Or you could go with the mamba system which is very good also but there are different motor sizes. The 7700 would be too much on dirt so you'd probably go with the 4600 or 5700. But you could also go with the 5700 with a 11.1V lipo and have a fast fast street machine also. Can't recommend batteries till you know what you want to use it for because some awesome lipos only come in a 7.4V version. Kinda see what I mean... each will have their strengths in certain arenas. Narrow it down a little for everyone and you'll probably get better responses.
Tamiya TRF417X (Lion's Automotive GTR)
Tamiya F104W MP6/4 converted to F104X1 (Renault R30)