What's the best option for water for tea in the office?
Either buy a cheap electric kettle, or if you are really fussed about not re-boiling water then shell out a bit more for one of the single cup hot water dispensers like the Tefal Quick Cup or the Breville Hot Cup. 

We have both a cheap kettle and a Breville Hot Cup in our office. The kettle is good for making cups for multiple people at the same time, the Hot Cup is good for a single person.