Sounds like two Powermasters, one for each level. You can wire them in series between your existing power supply (supplies?) and the tracks they feed. Lionel sells a cable for that, or at least they used to that had an inline fuse to protect the electronics in the Powermaster. Or you can try to get a few of their 135w or 180w bricks that have a circuit breaker built into them.
The blocks for switching between levels ought to work the same as they do now, but that can be added to the cab-1 as well. That would require a command base and a BPC I think. I'm guessing that if the blocks aren't used too terrible much, that would more money and hassle than what it's worth.
Hope this helps,
J White
