Hey are you still working on your Colosseum hack? I've been playing around with ROM hacks since 2007 and I'm pretty freakin awesome at scripting if I do say so myself I'm working on making my first complete ROM hack right now, however I saw your post and I wanna help you a little if I can.
If you haven't thought of a way to snag shadow pokemon yet, I have some ideas. I also have some sprites laying around. And maybe I can help with any other scripts you're having trouble with. Just let me know I wanna see this hack succeed!