Sanddrag,
In the last 15 years or so, electric meters have evolved from "simple" to quite sophisticated. With the advent of digital signal processing and all, they can be quite functional. Many are capable of near-real time monitoring, data logging, phasor display, voltage, current and power factor, communications, etc. Of course there are instruments that can far exceed them, but the cost of a meter is relatively low. There are also other moderately priced monitoring devices that might work better in your application. Shoot me an email, and I'll see if I can't put you in touch with someone in your area that has a lot more hands-on experience. I've worked in a business that was related to utility metering for over 20 years, and I know a number of factory people (from GE, ABB, Schlumberger) regional sales reps and guys who work in the metering departments of electric companies across the U.S. What you need does exist, it's just a matter of finding the most economical solution.
Assuming you are still around Glendale, one guy I'd recommend you get in touch with is Mario Natividad at Applied Metering Technology in Whittier.
http://www.appliedmetering.com/
(P.S. Large motors are 100 hp to 50,000 hp. Very large motors get up to 100,000 H.P.)
If you do need a used meter, I know the guys who are in charge of changing out about 9 million meters for Pacific Gas and Electric's Automated Meter Reading project. We made the software that the meter exchangers are using on their Pocket PC handhelds.