The Hella DE's are probably the best way to go. Less hacking involved. All you have to do is fabricate mounting brackets... which Moncha has already done a write up on based on his install of a set of standard DE halogen fogs. Same housing as the DEs in HID flavor.

Also... NHTSA made a ruling recently which makes retro fit kits or homegrown kits illegal for use. This basically gives your local DOT an excuse to fine you. If you use the DEs however, each state has their own rules on auxiliary lighting... so you can probably get away with it.