I got my Typhoon III from airwaterice.com. I love it! 10 micron sediment filter, to 5 micron carbon block to 1 micron carbon block to RO membrane, through DI resin and 0 TDS out. The whole unit came pretty much hooked up and ready to go. All I had to do was hook up the supply line, pure water line and waste line to it, which required no tools. You pull back the spring-loaded connector, slip the hose in, let go and the line's installed.
The toughest part was hooking the supply line up to my old plumbing. I have a larger, steel pipe that the supplied fitting wouldn't pierce. So I had to go to the hardware store and get a larger one. Then I just had to shut off the main water supply, drill the appropriate sized hole in my water line, then screw the needle down into the hole and tighten it down on the gasket. Just remember to hook up one of the supplied ball valves in between the water line and the unit, so you can cut the water off to it easily when it's time to change filters. Changing the filters and DI is a breeze too.
I use a large 30 gallon rubbermaid tub for water storage. I just installed the float valve at the top and it works like a charm.
It also comes with a decent amount of water line for most applications and a hand held TDS meter.
Oh yeah, I saw on their site recently that now they sell better units for less than I got mine for.