Well this is the actuall bulb I got.
I know that this is sold as the standard white fitting here in Australia. I am still thinking of getting another as they are so cheap compared to the others I have found and it looks quite natrual for the tank I feel. I have 3x150W M/H over my 6 Foot tank, with 4x28W C/F and 2x18W C/F (AquaOne light). I was thinking I could offset the colour with the C/F but I just wanted to make sure that the 4200K is ok for the plants.