I got mine on eBay. It was pretty cheap, I don't think I spent over $20, shipping included, and the seller supposedly handmade it. All I know is I really liked it. I wish I could remember who I bought it from, though, sorry I can't be more help.
I've used etsy.com. Most of the people who make it for you allow you to choose colors you wish. Each color of yarn has a number, give them that number just to make sure. It took over a week to get, but the product is great. I'm wearing it right now, i plan on getting another since my hair is at 10inches now.