Custom computer cases will cost you both arms and both legs ;)
koolpcmods.com used to do custom work I believe for fan grills, but I think they are out of business since the website doesnt work
Might find a local shop or person taht has a laser cutter tha could do the cutting for you.
If you want a ton of them, you might look at getting your own laser cutting system since it might be cheaper in the long run.
Mike
casearts.com will do LARGE orders for custom stuff. I think they just paint though. NICE paint jobs!