Well just a little update. I ended up taking the bumper off, and I found an awesome place to put the ballasts for a totally stealth install. Take off the little baskets on the bumper near the foglights and hollow out some of the dividers.
Only problem was the wiring from the ballast to the bulb wasn't quite long enough (grr). About 2 or 3 inches short.
I got frustrated and put the car back together. I ended up zip-tying the one ballast to the metal bracket the power steering resivoir sits on. The other ballast I have by the headlight laying flat between the battery and the metal under the headlight. I also zip-tied it. Both appear to be very stable, dry, and are definately not going anywhere, so for now at least I'm good to go. Plus I managed not to drill any holes in bodywork.

I'm sure I'll end up tinkering with them more later.
As for the lights, they are awesome. I have a really nice cut line, and no apparent glare problems. I drove about 15 miles on busy streets and not one person flashed. I also looked at them from several distances and no problems.
These are Denso/Toyota ballasts with rebased D2R bulbs. I got them from Ebay from a user named Integra9006HID. Everything was put together well and if you want HIDs I would definately suggest getting them from him if he has some. The whole kit was only $303 shipped.