As to time & cost.....one 20 minute of all EM lighting, and 50% test of the fire alarm Then 3hr test of Em and further 50% of fire. testing to including, call points, smokes and heats using solo equipment. Test of batteries, using discharge method, and not a multimeter. Test and operation of control panel, interfaces for shutdown, and as this is a block, check entry system opening and any extraction vents. Would suggest Electrical scam certificates for fire alarms, do not really contain enough information, so worth adding test schedule, showing check list of tests and values measured. A note can be then added on cert stating "see testing schedule for full report.
Depending on size, at least 1 hour for first visit, and has to be 3 hours for second, plus travel, time writing certs, smoke cost....big blue chip company £300+, decent firm £180-£240 per year. Insurance company will need to be informed as you will require added insurance categories to cover you works ....hope this is some guidance..