I drilled and tapped my moon discs on and never really had any issues. I put nylon washers behind them to keep from rubbing, and lock-tite in the holes to keep the screws from backing out. If you go this route you're in it for the long-haul though. It would be a pain to later fill the holes and re-paint the rims.
I would check your set up often, they're going to loosen up a lot, and those clamps are going to wear through the rims' paint (and possibly the rims themselves) over time
Here's the link to my moon disc install on Ron Burgundy if you decide you ever want to go that route. It was pretty easy as far as mods go:
http://ecomodder.com/forum/showthrea...tml#post485077