Well, sounds like a job for a 'speakers-on-a-stick' along with at least one sub bass cab.

I'm thinking along the lines of the Mackie MR450's (or simular) which on there own sound fine - so would be ideal for a small minimal situation.
Then when required the sub cab used when you need more 'humph'.

Anything bigger might be a job for a local hire company to handle.

There's been disussion about the Bose PAS on one of the newsgroups I watch. Basically - best avoid! Anyone singing their prases may well work of Bose, or a music suppier trying to shift the things.
I'm not dismissing Bose, I started my with a an 802 system with the bass bins. Would be still an ideal system today (if you can afford it). The PAS personally doesn't cut the mustard.

Try before you buy...