I have just received some excellent sporran straps made to my specs by Greg Woods, of Conneaut, Ohio. I found him through eBay:

http://cgi.ebay.com/collar-and-leash...item20aeb4b221

The straps are made of very nice bridle leather, with heavy brass hardware. They ended up costing around $25 each delivered. He will make whatever you want. He used 1 inch leather for the back belt section and then 1/2 inch sections for the front. If you don't make your own, you might try his...
MacLL