[BrianG]

I would be careful getting a used buggy, you might end up spending just as much getting it to new-ish condition than just getting a new kit.

As far as conversion ease is concerned, they are all pretty easy as long as Mike has the mount pre-done. Stick to the normal sized batteries and one of Mike's preset trays will be perfect. Even if the lipo is a different size, he does have the custom tray option; just provide the measurements.

One last thing: A typical buggy doesn't have much room under the body, particularly on the sides. So make sure you keep this in mind when you select your batteries. Sometimes, you still don't have quite enough room, but that's pretty easy to fix with a spacer under the body mount.