Electric shower or water heater

[gailkm]

I am installing a shower and basin in a small room at the top of my house, which has mains cold water supply with reasonable pressure but no possibility of hot water from the hot water tank on the floor below. As the cold water tank is also on the floor below I cannot get cold water from this either. It seems to me that my choice is either an electric shower and a small under sink water heater for the basin or a larger powered, electric instant hot water heater eg 12KW. I know these can supply both shower and basin.
I have 2 main questions:
1 If I choose the 12KW water heater, can I have a mixed shower if not, what else is there for me?
2 Does anyone have experience of any of the above options and if so, what would the best showering experience be, as this is my priority
Thanks

 

[Newboy]

Why not install a negative head pump and use your existing hot and cold tank supplies

 

[gailkm]

Why not install a negative head pump and use your existing hot and cold tank supplies

However, this is not possible because of the layout of my house. The hot and cold water tanks are not just below, but also in another part of the house and though technically possible to 'transport' the water, it would be incredibly expensive and a major upheaval

 

[Newboy]

Assuming that you can get mains water supply to the new location (and a suitable route for waste) then why not fit a small under-basin water heater and an electric shower

http://www.screwfix.com/p/ariston-europrisma-2kw-10litre-usink-water-heater/75532

http://www.screwfix.com/p/mira-sport-multi-fit-electric-shower-white-chrome-9kw/82661

 

[gailkm]

Assuming that you can get mains water supply to the new location (and a suitable route for waste) then why not fit a small under-basin water heater and an electric shower

http://www.screwfix.com/p/ariston-europrisma-2kw-10litre-usink-water-heater/75532

http://www.screwfix.com/p/mira-sport-multi-fit-electric-shower-white-chrome-9kw/82661[/QUOTE]

Yes its a good idea, but I thought in terms of space, electrical installation and cost, one more powerful instantaneous electric water heater would be better. But not sure. I think I can use a mixer shower with the latter configuration, but not sure how the final flow rates would compare to that of an electric shower. The priority is the best showering exoerience. Any helpvery useful