I think it is not even close, you want the Paradigm. Why? Because you are on a budget, you have to be smart about things. Kef are 89dB sensitivity, Paradigm 94dB. This means you will need almost FOUR TIMES the watts to drive the Kef as the Paradigm. Quality watts cost money. There simply are way more and better sounding 20W amps that would fit in your system than the 80W amps you will need to be comparable with the Kef.
Of course, if you hear Kef and fall in love, fine. But pay attention to what was used with them. Will you have that? Will they sound as good if you don't? Experience shows it gets harder and harder to find the right amp once speaker sensitivity drops below around 92dB.