Try www.admiralsteel.com they have a very extencive selection of high carbon, tool, stainless, and spring steels in a plethera of dimentions just for knife making!! You can purchace off the net via credit card or you can have them send you a catalogue.
The only frown I've found ith them is there is a $25 min order but i figure that is no big deal. Just order enough stuff for a few knives at one time, no prob!!
Thanks and good luck!! Chris S