AC switching, monitoring...

My sewer's sump system has 3 pumps...

• 2 in big tank. These have float sensors and only turn on when the fluid level is high enough. Only one needs to be on at a time. Ideally, I should have a switch box install that makes sure only one gets power at a time, switching it back & forth every so often. Otherwise if one is installed just a millimeter above the other, one will always get all the work and the second will never go, and so they won't wear equally.
• 1 in little (rainwater?) tank. Also has a float sensor.

My deck is currently still torn apart because I'm still paranoid that once I close it, something will break again and I won't notice.

I'd like to be able to remotely monitor (and/or get alerts) about the pump health.

Here's what I propose (and what I need help on)....

Small Linux box (Mini-ITX or Gumstix) in a water-proof box, with WiFi, with serial ports (or Serial over USB), controlling X10 Universal Adapters (if they're strong enough for the amperage?), or controlling some relays.

So yes, I could do the switching between the two tanks from the computer with just a remote relay control, including varying the offsets, such that one pump doesn't always get the same hours of the day, but what I actually want to do is measure the power draw per-pump.

Basically I want to make sure the pumps' floats and motors are still working, by measuring the power draw on each of the three plugs.

Any ideas how I can measure this?

I'm also willing to pay somebody to build me some Serial/Parallel/USB device to do this, if any CSE-types are out in the audience. I'd rather spend a couple hundred on a solution that makes me happy, than spend a few hundred on a switching box and seal up the deck and never know if it's going to blow up again (or already has!).

Thanks!