I can have my new tank drilled for a three or four hole closed loop system. My question is this. Several months ago, the Tank of the Month on Reefcentral had a rather nice water flow system that utilized the flow from the returns as well as the close loop system in which the guy used electric switching valves to alternate the flow. I am considering looking into this, but have no idea on the following:

1.) Where do you buy these valves?
2.) Are they reliable?
3.) Is there a better way to alternate flow? I do not like the look of powerheads in my main tank and they are too hard to hide if you want to be able to get to them for service.
4.) Should my closed loop system be three or four holes (one is for the outflow of water)
5.) Are these type valves a waste of money?