Your hardware and services quantities sound similar to our set up. The only main difference is we have 5 main sites, some 70 miles apart. We are an FE college which supports a rural community - South & West Gwynedd with approx 2.500 students 300+ staff)
My IT Services staffing structure is as follows:
1 x Senior E-Learning / IT Manager
1 x Network Manager
1 x Network Officer
1 x VC / VLE Support Officer
2 x IT Techs
1 x Information Coordinator / IT Services Helpdesk
We can't be every at once regarding sites, however the above staffing structure appears to be working well, introducing a full time ‘helpdesk’ made the biggest impact – We received a grade one for support this term by ESTYN, and at last, are receiving some excellent feedback from staff and students. Wasn't always like this! It has taken a major restructuring, three years of head hunting and finding the right staff, also 3 years of winning staff over to major changes in policies and procedures which was the most difficult.