This thread was started some time ago, but it's worth chiming in to help the next guy.

If you upgrade to a 700R4 you'll have to wire in the lockup. I just installed the B&M lockup kit on my project, and am quite pleased with it. It allows for on-the-go adjustment of lockup RPM and allows manual override.

The trans will run without the lockup, but will run hotter and your gas mileage will suffer.

For those on a budget, I understand it can be wired with a simple toggle switch, but I would personally use a momentary contact button, a relay, and a brake switch, with indicator lamp.

I'm getting much more safety conscious in my old age. Last thing I need to be thinking about in an emergency situation is my torque converter.