Timing Light

I need to buy a new timing light my old Craftsman crapped out, I used it on the Kawasaki Z1 and it worked great. I would like to find one I could also use on my Yamaha DT400C. So I would need it for a 4 and 2 stoke, 4 cylinder and single cylinder, and 6 Volt and 12 Volt. There are features on the new lights that I am not sure about such as RPM and an advance dial and I don’t want to pay extra for features that I will never use or can’t use. The Yamaha has a 6 Volt system is it possible to power the light off of a separate 12 Volt source. Basically I’m not familiar with all the modern features on today’s timing lights and what will work for my application if any. Thanks