Okay, so are these the "stock" models, or the KI branded versions? £200 is a tad high for the former and £450 might be okay depending on condition. I'd be inclined to expect "mint" condition for both. The original 7200 went for about £300, the PM-17 was about £800 I think, the KI clocked in at £1100 from (very likely bad) memory.
I always thought the 17 looked very smart, but had the chops too apparently. The 7200 will give you 25w out of its' 95 in Class A. Although I think you can run it purely as a Class A amp (selector option). Can you hear them by any chance?