[xPhantom]

It's recommended to have a dedicated server, but you can always use a VPS aswell.. You can get a vps from many hosts. It's recommended to have a Linux VPS (SSH knowledge required) and you will also need a game panel for your customers. Like GameCP.com or TCAdmin.com

You can always get a VPS from:
DotVPS.net ( I have one, its good but needs a better firewall installed) domvps.com (havent tried it but looking foward to) serverFFS.com (DDOS protected, I have one)