I have to admit my 'go to' light is an Acton dialback. Its the most convenient because of the built in 'tach' rpm. Big convenience with the MSD since the coil negative can't be used. And almost as handy with the Ford type horse shoe connector on the AMC's coil because that requires a backprobe jumpered to the tach/dwell meter.
I have a Equus Innova light myself(Saved off the truck) I sold many . I can still get them. In fact except for the Mac branded products, I can get pretty much anything. I still have an account with a tool warehouse I used when in business.