Fortec cylinders are common in flats and some properties with small loft spaces, they are used in a lot of council properties.
Fortec cylinders are very low pressure systems which tend to be very problematic with todays taps and showers available on the market as most products will not function satisfactury.
The fortec cylinders are not really suitable for pumping to boost the water pressure as the volume of cold water is too low and will run dry and damage the pump.
The best solution for showering is to use an electric shower which is mains fed to avoid the issue with the shower head being higher than the cold water storage tank.
For taps that work with fortec cylinders for best function choose seperate hot and cold taps, or mixers with 0.1 bar pressure rating. With mixers you will need to have non return valves fitted to the hot water supply which will slow down the flow even more, also in lots of mixing situations the cold pressure will stop the hot from flowing all together.