Re: okay okay, i know this gets posted daily but....
Most of the larger KMs will smoke the same so once you get past around 22" its going to boil down to aesthetic value and any additional features you're looking for. I'm glad to see you're still open to the idea of a single hosed pipe and I'd strongly recommend sticking with one hose. Like Manjaco said you can always plug the additional ports while you're smoking solo, and if you need to purge you can unplug the port but I think that its a nicer social environment to have a single hosed hookah. When I smoke in groups I like to pass the hose while we talk and even if the groups get bigger(I've done groups of 5+ with a single hose) you can just extend the session if you haven't gotten to smoke to your liking. I've even gone as far as to set up two single hosed rigs so my friends can try multiple flavors. It all comes down to preference, so just pick the rig that catches your eye and meets your needs.
36" Al Falkher Solid - 36" KM Copper Heart Two Hose - 22" Temsah Mini-Wheat(a.k.a. Golden Nugget)