I hope you know what you're doing. Have you experimented with your rewritten dialogue and the mouth flaps yourself? I know most movies get heavy ADR, but that dubbing is done with the same lines as the on-set performance. Changing the script, when not done carefully, will look as bad as an old Chinese kung-fu flick with low-budget dubbing.

If you're serious about this, you may wish to try sites specifically designed with voice-acting in mind rather than here, such as the VAA or BTVA. Professional projects sometimes succeed there.