ETNyx On mailcow page I can see only one provider and it’s Germany based.
I’m not sure if this has changed in the meantime, but now four providers in Germany and one in Brazil are listed at https://mailcow.email/vps/.
I personally use https://www.exoscale.com/. It’s not the cheapest provider, but it has been very reliable for me, and they have data centers in Switzerland, Germany, Austria, Hungary and Bulgaria.
By the way: if you don’t have many users and leave out ClamAV and SoGo, 2 cores and 4 GB should be enough (under certain circumstances, even 3 or 2 GB may be enough if you only have a few simultaneous users, but I haven’t tested this).