Man, sore subject for me in terms of Craft Store/hardware/auto shop sourcing of tubes x(
I ended up buying off the shelf from a local shop. For streamer (baitfish) style flies, I stick to the hard saltwater type tubes. I have pretty much mastered tying sea habits on them, and they proved very effective on Dorado, skipjack, roosters, and one sea lion in the sea of cortez last fall.
http://www.flyfishingforum.com/flyt...c13ed4bafa9d00ff6984729c428bc63&threadid=8431 for a sample. Bad pic...
For steelhead, the softer type tubes, where you can just cram a size 4 or 6 hook directly into the tube have worked great for me, and are less of a hassle to work with. Buy the longest ones they have, as the price is the same for 10 pieces regardless of length :hmmm . The 2.5 inchers can be used to make lots of half to three quarter inchers for summer flies}(
If you can find the "high pressure guage" 1/8th O.D. nylon tubing everyone writes about in books and articles, let me know...
As to heads, just get standard cylindrical "live body" foam, cut it, and sand or grind to shape. Pre-shaped are expensive, and I don't really love the shape of any of them personally.
Philster