Is there going to be any problem with this set up?

At the moment theres a basic two channel mechanical timeswitch in the
kitchen and a wired 'stat on the first floor landing. The timer
switches both water and heating on together but manual over-ride
allows them to be operated independently. There are two motorised
valves in the airing cupboard with the boiler.

I want to put a ACL Tempus2 7 day timeswitch in the airing cupboard to
control hot water (i figure with a 7 day timer manual override will be
rare) and use an ACL Wireless Digistat3i to control the heating. IME
a 'stat is far more useful placed in your primary living space (ie the
living room) than a draughty hallway with few rad's.

Are there any pitfalls I haven't thought of? The boiler is a
Keston130. I figure it's going to take a bit of time to work out
what's what in the boiler cupboard but all the new wiring will be in
one place.

AJ