You can get Savage drop-in barrels with a 1:8 Twist in .243 for the Savage from Shilen or McGowan.  I have one of the Shilen barrels, but I'm waiting for stock for the rifle to get here before I can shoot it.  Prices for the barrels run in the $300 and up range.  You're not going to find a factory rifle with that fast a twist.  Standard is 1:10.  Savage has a non-standard factory twist of 1:9.25.