[Paul Merolla]

I wouldn't use anything but copper, myself. It can't be more expensive than the "snap together" aluminum stuff, can it? You only need 1/2", or maybe 3/4" if you're running it a long ways. The going rate for 1/2" (wholesale) is less than $2 a foot right now. It won't rust or break, and it makes the job look like you know what you're doing instead of Legos...I may be biased, though, since I'm in the mechanical piping biz.