If you are looking for a pattern to sew jeans, Vogue Today's Fit have 2 choices, Kwik Sew has very nice jeans patterns and there are probably lots of others. Denim should be available at most fabric stores.
Are you looking to buy a ready made pair or to make your own? If you are making your own, just use the treads you like and you are the master - they will be as fancy or plain as you prefer. If you are looking to buy this isn't the place for you.