Miller or DEC are your best bets. But if you really want to go cheaper, you can get a Bosal for about $500 from RockAuto. Be warned tho- Bosal exhausts usually are not made very well and typically have fitment issues. I bought one for my e36 and the flanges didn't line up at the manifold. I had to bend the pipes to make them match up. Also, it sounded like crap.