My job title, officially, is Hosting Engineer.
Role is, *everything*

I/We (small team) handle network administration, Linux/Windows admin and support, pre-sales technical consultancy, internal/external security policy (ISO27001 framework), troubleshooting, incident handling, bespoke solution design and implementation, the list goes on....
As I said it is a great way to get your feet wet.
Salary starts about where you'd expect for a fresh graduate (sorry, no specifics), but from experience there is a
huge potential to gain experience rapidly and prove your abilities. If you're good and work for a good employer you should be able to increase your position and earnings failing quickly (although this may be limited by the current climate).
Generally there are a large number of data centres in the London (and surrounding) areas. London/South England is outside of my comfort zone, but you could take a look at
TeleHouse,
RedBus or
2e2. Alternatively most of the 'service providers' and 'outsources' will have some level of hosting provision.
If you've got a local BCS group might be worth getting to the next event and asking questions there, attendees to the BCS usually have a fair number of contacts in every field so are good people to know for local knowledge.
Hope this helps, good luck in the hunt.