what is the highest psi i will need for my airbrush for painting lures? what is like the average maximum?

Some of the pearls that I mix myself require around 28 - 30 psi. Most everything else I spray from 18 - 22 psi. My Iwata has an air control on the brush, so some pressures are lower leaving the brush than what is supplied by the compressor however.

I use a gravity feed airbrush which allows me to use low PSI settings.  If I'm doing base coat painting I use 15-20 psi but if I'm doing small detailed work I'll use 10-15 psi.  The low psi lets me get close to the bait without splattering paint.

I would say 15-20 psi for 95% of the paint I use.