I had to dig this up, just for you! This is what I go by, when selecting a pump:
1-make sure that it's a centrifugal pump.
2-if it's a "self priming" pump, don't get it: it'll be noisier than you can handle.
3-Magnetically driven, centrifugal pumps are usually the quietest
4-The pump should have a max pressure (a.k.a "dead head") rating of at least 1.5 meters, the more the better.
5-The flow rating is pretty much irrelevant, but you'd be shooting for at least 300 gph (~1200 L/H) at zero height.
6-Don't even think about using a massive pool pump: there's a limit to the efficiency of these things.
7-Keep in mind the power source: mains (110 or 220 V AC) is easy to deal with. 12 V DC is a bit trickier.
I personally have a Little Giant model 2-MDQ-SC (max flow > 550 gph, max head: 14.6 feet) (
www.convert-me.com ) and also have two Johnson pumps (linked in my sig). Both of these are phenomenal pumps, but each have their advantages and disadvantages.
The Little Giant draws a lot of power, and is quite large, because it's a true mag drive. The Johnson pump is a direct drive, so it draws a lot less power, but has been known to leak.
I know that in europe you might be able to get your hands on a fabulous pump, relatively cheap, depending where you live: Grundfoss. They're used in water heaters.
