Light weight 1/8 buggy can use 550 long can SC motor, such as ten shock or tekin pro HD .... 4700kv, max 2s ... Still work, but may be not powerful enough ...something 3000kv with 3s isn't bad!
There is a new class of 1/8 E-buggy, called Super Lite.
The chassis is basically same as 1/8 E-buggy, only change is motor use SC (typical use Pro4HD) and 2S LiPo.