Headlight Conversion

I own a 97 Jetta GT. I was driving down the freeway the other day when a golf ball sized rock went through one of my headlights. Needless to say i need to replace the headlight. So i looked around and found that an OE headlight costs as much as a SET of custom aftermarket headlights. so I got to thinking and I want to replace my boring sandblasted headlights for a pair of BMW Halo style projector headlights. I'm not an idiot, I know that they aren't going to fit, so my question is, what would be a good ballpark figure for the kind of modifications I'll need. I'm probably going to need some custom fiberglass laid to fit them, hopefully without having to make any major changes to the front of my car. I guess the best thing to do would be to get the dimensions for both sets of headlights and go from there.

Stock up some duct tape.