Was also looking at the Tunze on BRS. there were a few bad reviews. like pump not shutting off. I have a nano, too much water would easily flood my floor and probably kill a few things.
The Duetto looked good and had many positive reviews.
you can use a less expensive pump, the aqualifter uses airline hose so the pump doesn't go in the water reservoir and since I use 5 gal water jugs, this is a very convenient set up.
You can see the pump and the project box in my cabinet (the kist does use two power sources, the left two on my regular power strip)
The float switches (yellow lines) and the airline tube in the sump.