Eno provides the Eno's Firehouse server for A-10C and Black Shark 2 flying. It is on v18.104.22.168. (For some Internet reason the server is down right now...) We will look at upgrading the version soon. We did try DCS World but it is still in Beta with some bugs that got in the way of our missions.
We do use SimHQ TeamSpeak server for voice comms. Not everyone who joins the Firehouse is a SimHQ member so some text chat may be used.
A few of the other guys will put up a server from time to time. Good to join the SimHQ TS server to see who's on-line and may be running a server - if their server is passworded then you can get the password from the folks on the TS.
Hope to see you upstairs soon!