I have a 500H head for my Durst 1200. It works nice for multigrade. I bet it will work grat for graded as well, but the speed of printing may be less? I'm not sure about the spectral sensitivity of graded papers, but I guess some are sensitive to blue light only. If that is so, one could easily remove the color filters (green and blue) in the 500H head and have a hefty 600 W halogen output, which actually might be too much for smaller prints.
My only gripe with the 500H head is the heat. If I'm lith printing I'm exposing for several minutes, and the thermostat shuts the head off every now and then. This might be an issue of my 500H head, and there might be a simple remedy, like cleaning the fan or something.
Now when I think of it, I don't know if this has ever occured during exposure of a print, or only during focusing. There might be a timer in the focus mechanism that prevents one from forgetting it or something.