What more?
Lots.
What kind of construction for starters, pitch of roof and that sort of thing. Placement of structural members remembering it is impossible to install an ESFR system in bays measuring 7 meters at heights you suggest.
What's your water supply? This alone will have a lot of impact on what head to use.
I wouldn't select a head unless I was prepared to design the entire system and you shouldn't either. Do yourself a favor and leave the design up to the qualified individual.