He is looking for a
10,000 watt DC generator, 240 volt, electric start and it can be
either gas or diesel...... Any suggestions or ideas?

10 KW AC generators are pretty common. High current diodes are also easy to
come by.

AC to DC using a single or three phase input along with a reverse connected
diode to catch the pulse when the coil is disconnected.

Too easy?

Earle Rich
Mont Vernon, NH