Sam you can get almost any color skirt you can imagine online, problem is the cost efficiency when you're only tying a few if you're wanting a bunch of different colors too. If you're only planning on doing a couple colors then it's pretty cheap tying your own. I get my lead for free and without trying to figure the cost of the molds or melting pot, my baits cost me about $1.20-$1.75 apiece, mainly depending on what hooks I'm using.
You'll probably be better off buying the jigheads because it's very time consuming and costly to first get into jig pouring with the melting pot, molds, lead, and tools you'll need. The paint adds up and it's time consuming to paint and bake all your own jigheads also.
I use floral wire to tie my jigs, I get it from a craft store. Not 100% what size it is but for some reason 18 gauge sounds right? Copper wire looks prettier IMO but it's also more expensive and I lose a lot of jigs.
Living rubber is round, and more stiff so it tends to flare out while at rest. Silicone skirt material is more supple and moves more while you're moving the bait.
Check this site out for pretty much any skirt color you could want.
http://fishingskirts.com/index.php?main_page=index&cPath=56