Over here in Mi, there are so many folks and shops who make and sell jigs for the Detroit river. 5/8's and 3/4 oz. There are alot of places to purchase them. But... depending on if you are going to use live bait or sizable plastics. You will want to make sure of the hook length. Not all are created equal.
As far as Jann's, yes they have alot of stuff. But watch the shipping. I ordered 2-6 packs of harness hooks. Came to like $10, they put those 2 packs of hooks into a large box, not envelope and shipping was $16. Last time I ever bought anything from them again. I won't drive there anymore either. They gave me a lame excuse as to why they did that. No reason to use a box when a bubble envelope works like other places use.
Real easy to power coat your own and cheap.