I've had success with O.W.I rock speakers for around pools. 99% of the time I'll us multi tone brown LR 203's. For the price and the look you get alot of bang for your buck. And with today's natural moss rock look that seems to be prevelant the multi tone browns blend right in.
I've always wired in stereo l/r l/r, as mentioned above and had great success. In fact I'm always impressed with our outdoor systems, and most importantly the clients are crazy happy, which is all of ours ultimate goal. My guess is mono is more fitting when there is great distance between the stereo pair. I've never done a mono system so I can't say but I know that the seperation of stereo sure sounds cool, even outside.
If someone could elaborate on the reasons for using a mono system outside, it would be interesting. Although the reasons may seem obvious, something always comes out of it that is unexpected.
CMack