hey,
in monstmike's shop you find a motor mount for mugen. further you need a battery tray, I think he's got one, like that U have the basics.
and the rest is not that difficult, find a place for the esc (I have mine on the steering servo to keep the weight towards the front). You don't really need a conversion kit, you can do it like that. mike has the neu lipos, which are supposed to be good & not too expensive (your one-stop-shop
).
a mugen is a good idea I think, its quality should be good enought to handle the power (tranny).
flo