My .02 cents is that you should go with the newest nightly. Get it here.
CM7 updates
It's not 100% stable but it does fix the deep sleep issue and improve battery life. I like 7.0.3 but the better battery is crucial for me.
As for the numbering, look on the page I linked. I think 7.0.3 (the most recent stable build) was around 65 or so. It came out on May 8.