I actually already did this! I put the springer 5shot on a longshot, but one problem: Literally all the plastic for it warped when i used superglue. I think it was because the plungertube had DIRECT contact with the superglue.
Edit: Just wanted to note that i ripped it off with pliers afterwards and threw it in the bin.
To buy megas and arrows #1 just check ebay, they pop up pretty often. And #2 To buy them directly through this site, you need to use the trading forum section, which isnt open to you until you get full site membership.
Also, im pretty sure 99% of us know what it looks like.