I bought a pump. It's a Robinair 15151 (European 230V/50Hz version of the 15150). It can pull a deep vac that is quite sufficient for my app. I bought it over the internet at Fotronic. Only $ 133! (If I had bought the pump over here it would have cost me some € 700!!)
Next I need a vacuumtank and a pressure-switch. I'll come back on that soon.