Has anyone done a custom proton pack or a custom thrower? I'd like to see and hear about them if you have. I plan on doing my own custom build and am looking for ideas. Also has anyone found any real good substitutes for items on the pack or gun?

There's been alot done actually. Best check over on GBfans. There have been alot of custom slime blowers, packs, and PKE meters lately made out of pretty chep and common stuff.