same boat here roids - I am planning on making a fiberglass plenum for my quads also, basic plan is to get a rectangle 10mm alloy plate machined up to run across the face of the quads with all the openings machined correctly and then build a mold off it with floral foam and then gets to glassing.... haven't worked out exactly how I will attach the 2 together yet as I have a few ideas on how to go about it....
The thing I need is a 100% accurate template of the the quads to take to a machinist to get the alloy cut.