You missed out of your list General Dogsbody which is a very vital role in the IT hierarchy of power.
CTO / IT Director (SLT Position) AKA General Dogsbody
IT Manager (Top of the ICT Dept) AKA General Dogsbody
Network Manager / SIMS Manager / <whatever specialist role> Manager AKA General Dogsbody
Senior IT Technician AKA General Dogsbody
IT Technician AKA General Dogsbody
IT Assistant AKA General Dogsbody
As for me I'm the ICT Network Manager, but I do often seen to loose the Network bit as I am responsible for a great many things that Jarrod listed in his list, but its a good title, must admit I am often introduced by the SMT as the ICT Manager to parents and stakeholders which is nice (wonder if its due to me wearing a suit when I meet with them)