Cdc - The speakers will have to be passive as Ron already has an amp and is only agreeable to replacing speakers. I know JBLs have a rather well deserved rep as being on the "bright" side of things. However, the studio that uses four of them doesn't have that problem. For whatever reason, their music never sounds harsh or tense. I had forgotten about Genelec and that's a good idea. I know of a DJ service store not far from me.
Duke - The speakers have to be no large than what would hold a 6.5" woofer. Will have 2-4 ea. Room area to cover is 19ft x 39ft. Hard to say how loud is loud. We'll have to bring some speakers home and try them. Again, the music will not be played anywhere near as loud as a club would. His amp is 100wts for 2 channel which should be more than sufficient, however, it is a mass market Harmon Kardon so I'll check that with the speakers. Most of these type of amps are badly overrated. Not sure of budget as Ron is still bummed out about buying "the best speakers in the world", Bose, and getting such poor performance. I've tried explaining some basic physics as regards speaker size, construction, and ability to reproduce the electrical signal being input. Ron's face just glazes over.