Thanks for the reply and valuable feedback Beepster, its much appreciated. You are not alone being nervous with the idea of using a computer to control things live. The singer in my band was very worried to the point we had a band vote. In the end, we decided to meet in the middle and go with a hybrid setup.
I'll be running 2 x guitars + bass (3 channels Sonar X2) -> M-Audio FW1814 as a sub mix -> house mixer. I have one MIDI channel setup MIDI control. Then we will run 3 x vocals + digital drums -> house mixer. I will be using a Behringer FCB 1010 to control TH2.
The PA is setup and we have been using this setup at practice with great results so far. I will always have a backup processor hooked up and ready to go in case something happens. This next show will be a beta test using the hybrid setup live. I will follow up with results to let you know how things went.