Wow! I just found Sight Reading Factory. Go sign up for your 7 day trial and check out their site. There you can generate hundreds of sight reading examples in a variety of keys, times and difficulties. You generate it for the instrument you specifically want too. Great for auditions and assesments! Then you can buy a year subscription for only $30! I'm going to ask for my school site to pay for it as its an assesment and classroom tool everyone can benifit from. Check out their site and do their trial to check it out, I'm sold!
Sight Reading Factory