I am air brushing spinner bait heads using Createx paints, any help on top coats would be appreciated.

I like Devcon 2 ton epoxy but it is a brush on method and you need to work fast. The 2 ton is listed as 30 minute working time but in actuality it is about 15 minutes until it gets thick and hard to work with. There is also KBS diamond finish but it has fumes and will require multiple thin coats so for me I like the Devcon as it is strong and clear but it is one coat coverage and self leveling so you don't need a drying wheel.

JMHO, epoxy is not a good topcoat for spinner blades.  It makes the blade heavier which affects performance.  It also pulls away from any sharp edge as it cures, leaving the edges of the blade prone to quick wear and chipping paint.  Moisture cured urethane like Dick Nite S81 MCU or KBS Diamond coat work better.  A single coat of Dick Nite will give you a topcoat that is equivalent to a factory topcoat in my experience.

On the heads i just use nail polish myself. Holds up well and can be touched up on the water with a short dry time if need be. I have changed colors on the water before.