For £800, I would suggest you looked at speakers other than those Kef iQ9s. Good speakers, but for the same money (unless you are getting them with a ridiculous discount) you can get much better for the same or a touch more and on the nearly-new second hand market you can get speakers that leave them for dead.
I tested every single speaker in that sort of price range I could get my hands on and ultimately I felt I couldnt justify the money over the speakers I eventually went for, the Mission M35is. Everybody is an individual and money means different things to different people so maybe you will find it easier to spend that extra £500 - only one way to find out!
As for amplification, that would depend on three things:
Budget (I could assume it would be £800, same as the speakers but thats probably not the case)
What music you listen to (it makes a HUGE difference)
What is your source going to be?