Help with shaver and inline fan wiring

[Mini1961]

HI are fitting stud work for our en-suite and at present only have a supply above the ceiling for the rose it is on the last feed on the circuit so plenty room in the rose, i want to supply a shaver socket with mirror lighting as have not fitted plaster board yet, in roof there is a tile vent above the room and was thinking of instaling an inline extrator there will only be a shower in there no bath, what do i start with first i was going to fit a light switch outside bathroom with 3 pole isolator above going to have them on together, ps i brought a flush mount humidistat extractor (so i thought is two inch thick) to go in there but looks to deep for ceiling, as i was thinking doe's the inline come with a humidistat,

Help please needed from all you great sparkies out there

Thank you