I replaced the pump this evening, only about three hours work all in. There's two points to bear in mind if you have to do this yourself:
1. The workshop manual states the coolant capacity is 3.67 litres. This must include briming the expansion tank as I've changed the coolant twice now on this bike and have never got more than 2.3 litres in it, excluding the expansion tank
2. The workshop manual helpfully omits the fact that when you pull the water pump out from the side of the engine, you'll lose about half a pint of oil which will go all over the catalytic converter if you're not ready to catch it. I wasn't ready to catch it
Disregarding the two points above, this isn't a difficult job for the home mechanic if you follow the manual, the replacement pump includes everything you'll need and arrives fully assembled.
P.S. Fowlers rang me after I ordered the pump with a minor query about my order, while the guy was on I asked him if this was a part they sold a lot of. He said it looked like it as it is listed on their system as a part that they always try and keep at least 3 in stock.