Im debating getting myself and my girlfriends 2 sons each a 1/16 Summit VXL. Can anyone please tell me what are mandatory upgrades and what are recomended? Her sons are 4 and 6 so im going to be slowing the kids down to 50% power. We will all be using 2S lipos. Im not in any way new to rc. I just drifted away from Traxxas and let racing 1/5 scale take over. Now that the kids are big enough and want an rc im going back good old faithful Traxxas for them. Thanks for any help.