i'm in bad need of a loud and clean sounding PA system... my drummer plays freaking loud as hell and i play through a twin reverb now while my bassist is playing through an 100w ampeg. so the vocals need to be louder. my price goal is around 500 or under and we play mostly fast funk/jazz with rapping involved so you definitely need to understand what the singer is saying...

go for a Kustom PA, it helps to save a little extra money...i worked 2 months straight when i was 16 (just last year) and was able to afford this lovely system:

double 15 inch 600 watt cabinets = awesome
Ibanez MTM2 (DiMarzio X2N/Paf Pro)
Ibanez JS600 (EMG 85/81)
Ibanez EW20AES
Madison Divinity II
(2) Vader 2x12"
Korg Pitchblack
Ibanez TS-9
Boss NS-2
Roland GR-20