Patch panels are available from all of your favorite Porsche mail-order outfits. I have a favorite--I work for them part-time. (See my sig for details.)
Most of the metal 914 parts that anyone sells are actually made by Restoration Design, so no matter where you go most of the parts will be the same (generally high) quality. They sell at retail, though, so no price break that I am aware of buying direct from them...
--DD
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1974 VW-Porsche 914 2.0 (Type IV powered!)
Pelican Parts' 914 Tech Geek http://www.pelicanparts.com