True Sine Wave Power a little OT

I'm looking at getting involved with a diamond press. The prospective lead engineer has quite a bit of experience with the mechanical end of things, and a little with controls. He suggests that to provide heat at the right moment, we need a true sine wave across the load, and the best way is an AC generator coupled with an AC motor driven by a frequency drive. Have any of y'all seen a canned outfit like this, preferabbly one I could send a 4-20mA signal to, and a 4-20mA signal back from for the power used?

Apparently, theres a bunch of those companies in your area.

I have seen a diamond press power setup that consisted of a motor operated variable transformer. The output of the var transformer then fed a stepdown transformer for heating the graphite. The transformer wiper was moved via servo-motor.

I did not notice who made it, so I cant be of much help, but it looked European (IEC) - not to mention it was several years ago.

Surely there is a better way to do this though. Why not use a SCR power controller and precision metering equipment?

I'm not an expert, but if you are creating heat through a (presumably) resistance heater the type of current - DC, pure sine wave, or poorly defined AC waveform - shouldn't make much difference. If you are using an inductive heater then the sine wave form may make a big difference. Have you contacted the source of your heaters for advice?