I just finished laying the floor in our attick, now for the false ceiling above it.
We used:
http://www.atticladders.com.au/
One thing I found when shopping around, the weight ability of the stairs them selves. These guys have a model which we had fitted which takes my weight plus something heavy in my arms.
It cost $1400 fitted and mess cleaned up, waited 3 weeks, friendly agent bases in Brissy who did the job well, took 4 hours from start to finish tops. Pleased over all.
I suspect a 3.6m ceiling may mean added costs. Not to sure.
For a flooring, I used 19mm Yellow tongue boards. They have a water proofing on one side.
Please just keep in mind weight distribution when looking at this. Also watch out for power, phone, and TV cables etc.
Most newer homes are trussed, so they have a range of stairs which fits neatly in the space given, but also, not all the gaps between the trusses are even! Nor are the trusses parrallel either.
TIP
Measure each board individualy when cutting to size for the flooring up there.
Over all, we gained 24m square of space for our stuff, with another 11m available, got lights and power too.
I did all the work, but not the stairs fitting, easier to get them to do it, Go Finshing as a wise man suggests!
Well worth it.
Question, do you IP types think this could add value? Or even saleability?