There are a lot of companies on the net offering webhosting services. There are a lot of different plans covering a broad spectrum of options. Storage, bandwidth, OSs... the list goes on.
OSs... the majority of sites that I've visited have advertised 'your option/preference' of OSs on their servers. Unix/Linux (some ARE specific about which) or Windows.
Just curious... what's your preference?
There are various companies providing web hosting or domain hosting packages. It depends on what kind of server you prefer whether windows based or linux based. 101domain also offers good web hosting packages.