If you are sure you only need vocals only......building an easy to use, powerful handy PA for that use should be easy - weather you go powered or passive speakers. I would recommend learning the limitations, and also recognizing the pluses. I use stuff on a stick and two monitors for a lot of rooms, where volume is a concern, space is limited, and or access is difficult.
I use light weight speakers, and a powered head in this capacity.
I just posted this in another thread - regarding hiring for sound - if you know someone - it might be helpful, especially in learning about the equipment and setup/use.
In all seriousness -
for what you are asking for - why not ask a guy who does his own sound for a local band that has adequate equipment? You won't need to pay a "pro" level guy, and will be giving work to a guy who is already pretty good, and might appreciate the work.
I got/get a lot of work that way - and am by no means a "pro" sound guy. I have a very decent system but not a premium system. Depending on the gig, distance, etc. I give some of the guys a little break and they still get good sound. They help me load in/out as part of it, and everyone wins.
Before anyone bashes this idea - it works for me and several people I work with. I refer jobs too big for me to pro guys, and hand off dates to free-lancers. I stay pretty busy for a guy with a day job too.
