The PEX and all fittings are from Menards (local big name building
supply). The label on the PEX is CPI Dura-B PEX. Every once in a
while they have the reflectix and PEX on sale, so I bought them both
for a pretty good price.
The aluminum plates were bought direct from All Foils Inc.
(www.allfoils.com). I bought the plates unformed, and built a simple
jig to press the shape into the plates, using a mallet and a home-made
die (made out of 2 x 4's). Works just great. I just have to remember
that each swing of the mallet saves me about 10 - 20 cents! If you
tell them you need plates for staple up radiant heat, they will know
what to send you. I think it was 8" x 16" x 0.012", untempered.
By the way, I live in North-Central Indiana, if that is of any
interest. Sometimes that is nice to know when evaluating a design.