I need it for a Glock 17 with a Surefire X300 Ultra.  Looking through their available options all I see are options for the X300.  Tried e-mailing them but no response.  Does anyone know if it'll work?  Any suggestions?

Yup.  I run a standard 6004 and just pop out the plastic disc.  The light stays within the holster but the disc interference fits on the inside so it must come out.

Ok, I'm looking at the 6005 model.  The site I'm looking at ordering from only has the option for the X200 model not the X300.  Does this make a difference?  I'm looking at that site because of a discount I'm eligible for.

I'm running a Glock 22 (same dimensions as the 17) in a 6005. I use an x300 light, but the holster model is for the TLR-1 light. It works perfect, don't have to remove the disc in the end either. Not sure of the dimension differences between the x300 and the x300 ultra, if any, but the TLR-1 is slightly bigger than the x300 so there is a little room. No wiggle or problems though.