I'm wondering if the OSRAM HQI-TS 150W/D bulb would work with 120v US voltage... Looks like the few places selling this bulb are located in the U.K. Are the bulbs only compatible with 230v english voltage or can they be used in countries with different voltage?

Bulbs are pretty much universal, I think.
It's the ballast that fires the bulb that has to be US compatible.

You can use any 150W metal halide electronic ballast, or use the specified magnetic ballast for that lamp (ANSI code).

I, personally, prefer ceramic metal halide lamps over quartz.

Excellent! I'll give it a try.