I would be keeping my powder dry for now, because it is apparent from the Gov website and mutterings in the press that hybrid heat pumps will most likely fall under the subsidy scheme in a year or two. This is a much more viable solution for many UK houses, where the heat pump does what it can and a gas (or oil) boiler tops it up. More complexity at the sharp end, but no need for a storage tank, and can use exactly the same rads as a standard gas system.
I priced it up for our house using a bolt-on to our existing WB gas boiler at maximum £8K. If they start subsidising this and equalising the price of electricity v gas per kW, then this could get very interesting.
A hybrid heating and hot water system is a combination of two or more technologies generating heat to provide heating and hot water to the home or building. Learn more about hybrid systems
www.worcester-bosch.co.uk