Tri-channel
These system look like they are designed primarily for esthetics.
The close proximity of main and center channels is equivelent to setting all 3 speakers right next to each other. The small drivers in this type of speaker also limits and performance and frequency response of the speakers.
If asthetics are a major concern, look into onwall or inwall speakers for your HT. They can be painted to match the room making less obtrusive than bookshelf speakers and brackets.
Another option for a single speaker enclosure below the screen is the Yamaha sound projector. Multiple drivers in different directions will simulate the surround sound effect in a square room. See the Audioholics review for more info.