in HS 4 it's like in the "real HF world": There are no selectable servers as well. ;-)
The current server (you are working) is depending on your location / QTH, in your case maybe Düsseldorf, Frankfurt, Köln or München (we have in Germany with 4 servers the most HamSphere servers all over the world now).
It is not necessary to buy many plugins/antennas - to make good QSOs. Just be patient and look ahead the propagations.
In HS 3 it is not "real" (more like Skype and so on).... on a real radio you can't change a server / your location.
We always have to live with the current propagation - and it's the same on HS 4.
Beste Grüße in die Nachbarschaft. :-)
73 and good DX from Jörg :-)
Bochum / Germany