I have an 11 year old who loves shooting. He's not super careful so plastic is his friend. He found a comic themed AR and wants to do something similar. The donor rifle is a S&W sport ll with a Sig Romeo red dot. Thinking about changing the upper to something a little cooler, different hand guard etc. Even considered different caliber, maybe 9mm. This isn't a Belgium made Browning or 100 year old Winchester, so I'm totally out of my wheelhouse. A little help here for ideas? Budget is 1K or under. Apparently only real requirement is that it's Deadpool and the magazine looks like it's loaded with burritos???