What is the difference between ignitions?

Especially MSD. They have several diffrent ones. What about the Mallory Hy-fire? I will be useing nitrous. I would also like one with a built in window switch if possible.

I think the best money I've ever spent was on my MSD digital 6 box. Granted it is kind of pricey when you can have a 6AL for half the price. But it only retards the timing when I spray it plus a soft touch rev, 2-step, and a starter saver. Nobody has anything like it for the money.

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95 Z28 6 speed
Sprayed with other go-fast parts.