I'm from europe.....we use a lot of DeSisti but we don't have lightmakers.
The head connector is easy to change, ovviously the connector on the ballast not the one on the cable that is factory connected....
Here in italy connectors are different, Arri and Powergems has one and Desisti another, but the pins are the same, so if you mark them you can easily change and recable....in therms of qualily i really don't know, but in my experience Arri are 10, new desisti are 5 with problems of flicking at extreme shutters like 45° and power gems are cheaper with a lot of problems....
Hmi are a strange equilibrium of ballast, Bulb age and input frequency, just think about the fact that a virgin hmi bulb takes at least 2 hours of work to go on the °Ktemp declared (6000 °k) due to the chemycal stabilization of the elements and rare hearts the frist striking is about 10000 °k
So try the ballst with the fixture and a good bulb, but this can't avoid future electronic or electric failiure of the unit.
Change elements on a ballast can be easy if you can really see what is the problem (burned or broken connector or parts) if it's an invisible probelm you need an expert....but a real one.
Another question is that i'm not sure if the electronic part of the head can properly work with a lightmaker ballast, properly means that you can strike it but the factory standards are not garanteed, like brilliance hot restrike or dimming but also color temp and power factor, uh, does the lightmaker ballast has a high power factor? (must be written on it volt,ampere,watt and power factor expressed in cos of greek letter Fi)
I hope you can understand my italian/tecnical/english
I agree with Tim for a beautiful, Arri square wave magnetic ballast heavy like stone, you can also uses instead of sandbags
Gaffer Rome Italy