First you will need dual power rails at +/- 170 volts (assuming 120 VAC, for 240 you'll need +/- 340) capable of supplying 1k5VA continuously (more is better).
Next, the easiest method I can think of is to use a microcontroller with PWM hardware to drive an H-bridge.
Some feedback to track the voltage and current among other things will help keep it stable.