Great, I want to go hourly, or if staying salaried I want to be paid as if hourly. That means I'm paid 33% for all time that I keep myself available while on-call, and paid 2x (or more?) for time spent actually responding because it's after-hours overtime.

If I'm going to be 24/7/365 with no backup and get crap about "I'm not paid for you to escalate to me at night," you're going to pay through the nose.