Hamilton Lighting still sells the M80 ballasts that you're talking about. I recently got one for my 250W Radium.Electronic Ballasts are great for ease of use and flexibility. I know they tend to underdrive some bulbs, so I do prefer Magnetic HQI ballasts when running 250w DE bulbs or SE 250w Radiums. The magnetic ballasts seem to burn them for a couple months longer and definitely produces a crisper, brighter light. I'm not sure if the good ole magnetics are even readily available these days though. The electronics may be the only choice and I agree that luxcore would be an excellent option.