Stator problems are pretty common on the older KDX's. A rewind will be cheaper than a new one. If you find a good shop, they will probably use better wire and do a nicer job than Kawaski did.
You might bring it in to a small electric motor shop or handyman (vacuum repair/electric tool repair) in your area. They will likely have the wire and everything else they need. Even if they have never done a motorcycle stator, they should be able to figure it out quick.