4S is sick!
Forgot to mention most of my runs were on pavement. On 4S and offroad you'll really need great tires and a smooth throttle control, not really good for racing.
What brand is the BEC you're getting? I might get one of those and get rid of the receiver pack.
Also, since you'll use 4S have you decided which motor to get?
If you get a buggy, bear in mind some do not have a lot of space for a 4S pack. On stadium trucks you can just add velcro straps, but on the buggy the chassis may interfere (this was the case with my kyosho lazer, the 3S pack would barely fit).
some foreign cheap brand i would imagine, i think its for
planes but meh. i got it on ebay. just type in bec or ubec.
mine i think is 5-30v input 5/6v output. cheaper and easier
than a reciever pack i reckon.
the whole system is going into a 1/10 S/T and i will be using
the velineon motor 3500. should haul.
as for the battery fitting, it will be a bit tall but if i have to
duct tape it in a sock (my personal fav) i will. lol. she'll go.