Yeah, that's what I wanted to hear. I think my suspicions are right, I need a 4x10 pushed by some decent wattage. I'm not expecting PA systems that could carry the bass (though that would be nice). Definitely no PA for the kid's school band stuff. I believe it's 30 piece jazz band, I just want him to be audible against all those horns.
I'm gonna pick up that Hartke setup and if it doesn't work out, lesson learned. Thanks for everyone's advice.
"All the science I don't understand is just my job 5 days a week"