Yes there is a tool to hold the balancer (p/n is in the repair manual) but, these guys are right, using the starter is the best way for a real difficult bolt. The tool has a collar with 2 bolts that go through into the balancer and the handle locks onto the collar. I always use it to retorque the bolt but always wound up using the starter to crack loose the bolt. I put a jack stand off to the side and rest the handle of the breaker bar on it. I always put a piece of wood in front of the radiator just in case. It really isn't that bad for the starter/flywheel, you aren't going to hurt it. Just use a 6 point impact socket and take the slack out of the breaker bar before you hit the key. It only takes a real quick hit from the key.
Good luck!