We have in our stock about 300 DC-to-DC converters by Gamma High-Voltage Research. Their part number is MC-30. Their recommended use is for 12 VDC in and 3000 VDC at 2 Watts out. But more generally, they convert from a two-terminal input range of 1.75 to 12 VDC at 400 mA, to a two-terminal output range of 300 to 3000 VDC at 1 mA. Output ripple is typically 1% p-p.

Physical characteristics are as follows:
Dimensions: 1.5" x 2.5" x 0.75"
Weight: 4 oz.
Packaging: Solid encapsulation
Terminations: 4 PC pins (.043 dia holes)

These are available from us at $80 each in quantities of 1 to 99, or $50 each in greater quantities. Contact us for further details!