Instantaneous or Storage Hot Water Heaters

[zapata]

I have a small industrial unit that only has cold water. I'm putting in a domestic kitchen sink and need hot water in reasonable quantities at reasonably hot temperatures - about what you'd need in a typical household kitchen (sorry can't be more specific).

Looking to buy an electric instantaneous hot water heater in the 9Kw range. Preferably the type that can be mounted under the sink, using a standard tap, rather than the wall mounted type that goes above.

Any pointers? Anything I should watch out for or avoid? Any brands significantly better/worse than others to install or run?

Should I consider a storage type? Capacity of 10L should be ok.
Any advantages to the vented vs unvented storage?

Thanks in advance for your sage-like wisdom

 

[simond]

Our OSO rep just came round with a 15 litre point of use 3kW cylinder. OSO usually have a good build quality.