unfortunately ripping models from games like on Xbox360 is 'illegal' due to modifcations.. blah blah. We want them to make wicked armor to use for costumes, but that's part of the problem. I wouldn't dabble in it, when it comes down to the issues it's You and your lawyer (if it exists) vs microsoft and it's army. Not a good fight. Be like a level 1 fighting a 85.
However you do have some 3D talent there, even if you don't think so - I haven't even started 3D modeling, was hoping to but never got what I needed to, there are a lot of good modelers here on the 405th too, so try making your own stuff and seeing what they say, listen to pointers. This way you can 'free hand' whatever you want to use, and there is less legal matters to deal with. (still a copyright infringement, but most companies use us for free advertising instead of attacking us)
I have come to despise WoW itself, but some of the gear is so wicked I want to make it for costume purposes. Same with the game Last Chaos.
Back on track - looking forward to see progress photos!