Betmill is a good teaser book. If you play wiseguy teasers and win, they will restrict you to phone-in play.
You might also take a look at Hollywood. They take 3 dimes per teaser on the internet, and to my knowledge, they don't cut limits. They're also a good out in general with -107 lines. About 1/3 of the time, they'll have the best line on a game (excluding fake-line books, like Bodog and IIS).