Interesting question. I've been making steelhead jigs since the '80s. I agree that getting hooks and jig-heads has been a problem.
With the increase in jig popularity, more manufacturers are selling pre-made jig-heads, but the small packs they sell them in are way over-priced.
I don't know any retail store locally that sells jig-heads designed for steelhead in bulk or at what I consider a reasonable price. You can get them online cheaper, often.
The long-term solution is to buy bulk jig hooks (without heads). Make sure you get quality hooks- at least 1x strong.Local places (Sportco, Sportsmans', Sunbirds, Cabela's, etc) usually have them in 25 packs at a big discount from the small packs of pre-made heads. You can find them on-line even cheaper.
One you have the hooks you will need to put a head on them. You do have options here:
1) Long-term solution is to get a lead mold and pour your own, then paint and away you go. Fair amount of work and equipment involved, but worth in the long-run, imo.
2) Use a "bead-head" jig like this:

You need solid brass beads (quarter inch or so) and a sewing pin. Pin the bead and tie the pin to the hook shank and away you go. That was the way the originaL "Leo Jigs" were made and it stills works well. Actually my favorite way to make them.
Hope this helps. I haven't bought many materials on-line lately, but I'll do a search later and see what kind of deals I can recommend.