Outdoor patio speakers - pair or single stereo?

Am looking at installing outdoor speakers for my deck. Deck is 14' X24', seating areas tend to be toward the outer corners because of where the door is, so I'm concerned that the seating areas are to close to one channel or the other.

Am considering installing a single Proficient Audio dual voice coil, twin tweeter design (Model AW600TT) instead of the traditional speaker pair (Proficient Model AW650). Amplifier is Kenwood 100W/Channel. Here is speaker info:

6 1/2" polypropylene woofer
Two 1" supernil soft dome pivoting tweeters
Power handling: 125W
Frequency Response 35Hz - 20kHz
Wiring - 4-conductor (left & right)
Sensitivity 90db

Anyone have experience with these type of speakers?