Fitting cold light head on Omega DII

I'm interested in obtaining a cold light head for my Omega DII. I have a couple of questions that I hope you all can help me with.

First, where does the cold light head fit, in place of the tungsten bulb head on top of the filter drawer (with the condensers removed), or does the entire light head, filter drawer, and condenser collars come off and the head sits on top of the negative carrier?

Secondly, what sort of transformer and/or controller is needed? I have a Gralab digital (sorry for using a curse word!) timer that I like, but I believe I have read where cold light heads can mess up these kinds of timers.

Thanks in advance for your advice!

Depends on the head, but if you get the current style Aristo head, it fits in the aluminum collar in place of the condensor lenses. The transformer is in the unit, and there are two electrical cords--one for the heater unit that plugs into the wall, and one for the tube, which goes to the enlarging timer, and which might not work with your Gralab timer.

There are older Omega heads that work that take the place of the whole condensor head, light source, and all (everything above the negative carrier).

I currently use mine with a Metrolux timer, but I've also used it with an Omega Pro-Lab timer (one of the ones with the big dial).