904 dilemma, please help!!!

The only real difference in the lockup and non is the clutch inside the converter, so you might want to think about using it and having OD possibilities.
You don't have to use it to have it available.

For using the OD parts in the non OD, you would need to take the Pump along with both drums and the valve body to make sure you are swap safe.
(I think there are some differences in the front drum bushing as well as the input shaft besides the converter end of the shaft.) Not positive, so if you take all those you should be fine.
The valve body has an extra valve section that is responsible for making OD come on.

I'm sure there are a couple of people here with more recent experience that could tell you the exact details.