Will your ballast fire an HQI bulb? If so, that opens up lots of choices. Also, the 150w 6500k bulb on MD's site is an Iwasaki...I'm not sure it will work with a regular MH
ballast. If I remember correctly, these bulbs are usually fired with a mercury vapor ballast. Check Dr Fosters...I'm thinking they had some small base 150 MH
spots and floods in the 10k range? You might have to get a different socket, but those are fairly cheap. The bulbs I'm talking about would work best in a pendant type fixture.