I thought I would just update the thread so potential readers in the future would know.

The eBay ones work great, but the connection at the top was 1 millimeter too tall so I had to sand/grind it down. But after that, the plastic clip snapped into place.

I think it was well worth to get some less than half the price of the Arnott ones.

Something I learned was that pulling the 30 amp fuse nr 87 turns it off but putting it back in doesn't instantly turn it on again. Pulling the 7,5 amp fuse nr 79 out and in did instantly turn it back on.

EDIT: But the SELFLEVEL SUSP.INACT is still on, will it turn off after driving for some time or do I have to take it to a mechanic?