I have recently moved into a two up two down terraced property that
has no central heating. I would therefore like to have this installed
(not confident enough with plumbing so therefore certainly not going
to tackle gas).

One alternative, if you would like to get confident with plumbing, is to
install the system yourself but get the plumber to install the boiler.
Installing radiators and pipework really isn't very difficult. Lifting the
floorboards is the the hardest bit. For a completely new installation, you
could use plastic pipework (except the 20cm visible final run to the rad
which can be chromed copper) and run an easily subzoned manifold style
system. The amount you save in installation costs would easily pay for
programmable thermostats and zone valves for every room, along with fancy
vertical radiators and kitchen fan convectors, rather than a bog standard Y
plan with standard rads.

Christian.