I'm opening a bar here in Osaka, Japan and need a decent audio system for background music, party music, gaming, movie watching and possibly DJing but haven't a clue when it comes to audio equipment, so I'd appreciate some help on this issue.

I've got a room that's roughly 5x5 meters and I'm considering getting a wall/ceiling mounted powered PA speaker for each corner of the room (4 total) plus a sub if needed, then hook it all up to my PC directly, making it the source and the mixer (might expand later but this is the plan for now).

First of all, I'm not sure of whether or not this is a good setup. Second of all I've no clue how to hook it up. I figured maybe I could daisy chain the speakers and plug the first/last one to the computer with an XLR to Jack or something but apparently most speakers only have one XLR port so that's no good. How would you go about this?

Also I want absolutely no noticeable noise output.