switched 12v source for my Holley Sniper

I am installing a holley sniper on my Demon. This requires a switched 12 v source that stays hot during cranking and running. Everything off my ignition switch dies during crank or is only hot during cranking. Any ideas where i can find this source ? Should I just do a toggle switch type thing? Holley says this wire should not be piggy backed with other things. Forgot to mention i have installed a aftermarket kwik wire harness throughout the car.