Actinic 03's generally have a spectral peak at 420nm (dusky purple) and the so called 7100K peak around 450nm (bright blue). Current has a PC bulb that peaks at a slightly lower wavelength right on @ 460 (super bright blue), these are our personal favorites for actinic.

The choice really boils down to what colors you are looking to achieve. They will all induce the fluorescing colors we all love, each a little differently.

Not sure if this helps much....