For the "direct actuation example" (chapter 6) I still needed an alternative for the power switch tails (SFE COM-09842) because in europe there is largely 230 volts in the power grid.
Parts of SI 230-2
I found the SI 230-2 230 volts switch interface at ELV (thanks to Olli!) which you can either assemble by yourself (14,95 Euro/ ~ $21.53) or buy the already assembled part (24.95 Euro/ ~$35.90). I chose to build it by myself and it's quite easy to solder and put together. No SMD parts and everything fits very well. Only the instructions could be a bit more detailed.
You can switch the interface with 4-18 volts DC (6-48 mA) with a maximum switching frequency of 0.5 Hz which means you can switch every second or longer.
Assembled SI 230-2
It operates up to 230 volts with 16 amps - so you could drive almost everything needed in the house. The switch input socket is for a 3.5mm audio mono jack plug.
In the meantime I also built the "romantic lighting sensor" and will post the results in a few days.