My system works pretty good, but unless you are comfortable with fiberglass and fabrication, it's pretty involved. You'll find more info in my build thread linked in my sig, also check with sportfish, he built a similar setup.
I epoxied some 1/4" aluminum bar to the foam, glassed over that, then epoxied "T" track to the glass, then drilled and tapped the aluminum bar and installed bolts throught each end of the T track.
For the holds themselves, I used an old pair of work boots I duct taped over and then glassed to create a form. Then used some more 1/4" aluminum to form a backbone.
Here's a pic of what I'm talking about.