Peavey make a wide range of speakers, both Guitar biased and for PA, and the PA speakers I've heard/used have never let me down sonically. My current PA uses a pair of "Black Widow" 15's for the bass and there's absolutely no problem with them!
I use a Soundtech PL200 on foldback. Its a nice clean amp but you aren't going to smash any windows with 100W per channel, so dont over-drive it (i.e. make sure the clip LEDs NEVER light up) and you should be fine.
Moving the speakers sounds like a good idea.
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John Allcock