What boiler for 2 bathroom house?

[Spada01]

I'm just renovating a house with a bathroom and shower room. I'd like a boiler that provides a good flow rate (shower is of the overhead type).

I've looked at a few boilers - Ecotech 831, CDI30 etc. However, should I consider one fo the storage type boilers like this:
Glow-worm Ultracom 2 35 HE Store Combi Boiler Natural Gas/LPG