Shower Pump, Heater or Header Tank for top floor

We’ve just moved to the top (8th) floor of a 1930’s block of strata title units in Sydney and are planning a complete renovation in the spring including new bathroom and kitchen. As we’re on the top floor, we have access to the attic above where we plan to install reverse cycle aricon (with corporate body approval).

However, the water pressure is very poor for both hot and cold and the boilers are on the ground floor so it takes a long time to get any hot water (5 mins at times!) and the shower pressure is pathetic – in fact the cold water pressure is so poor you have to turn the hot down to get a reasonable temperature (once the water is hot). We have asked the agent for the building if it can be improved but we doubt it will make any difference as the water system has been recently serviced/upgraded.

So to avoid wasting water and to get a decent shower should we get a a pump installed during the reno, a header tank, a heater or a combination of all of the above?

Background info

The washing machines in the laundry also on the 8th floor have an external pressure switched water pump (with a small expansion tank) for the cold water fill which seems to work OK (the machines only use cold water).

Ceilings are 2750mm high. We have a structural engineers report that the extensive concrete beams (some are 500mm high 200mm deep !) and pillars in the walls take the loads – this means a tank could be put on one of the beams in the attic.