It depends on what he'll be requiring. Firstly will he be running the game server on his own computer or aim to run it from a web server? Or rather does he have a server already?
If he requires a server for the game, my points on it are these:
It probably cant be run on a linux server so that makes it somewhat difficult or rather more expensive, as most Virtual Private Servers resellers provide only Ubuntu or Debian.
I have now used a rather cheap Linux VPS for several months (rackburst.net) and the network is quite good. But I do not know if it is enough for some heavy game servers.
The hardest thing will probably be to find a cheap server with enough monthly bandwidth to provide game servers, as there will be quite much of transfers, especially if there will be alot of players. The options really these days are either buying a VPS that you manage and config pretty much yourself. Or then you could buy a server specifically for some game as providers like (
https://www.gameservers.com/game_servers/arma3.php) are selling. Usually these "specific servers are alot more costly than running a VPS.
If he just needs a server for the website:
Well this again depends, for if he already has a computer for the game server, he could just install apache to it and start running a website on the same computer, or then just buy a cheap linux VPS or a website server for it.
Domain:
Buying a domain today is quite simple since there are alot of resellers for them (Buydomains, Godaddy, Hostgator, etc). Using them in most cases are quite simple since the reseller provides usually some sort of a control panel where you can just enter a IP-address and they will handle the redirection.
For starters and testing purposes there are quite many free doimain providers, but usually those are somewhat ugly (ex. domainname.free.server.badexample.com). if you want a somewhat "beautiful" free domain you can get one from Dot.tk as they sell .tk domains. This would yield you domainname.tk address that you can use freely for 1-2 years.
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