The Infinity P363s are an awesome value but comparing those Infinity's with the Kef's, PSBs and Monitor Audio's is completely unfair. They just aren't in the same league.

The choice between Kef Q900s, Monitor Audio Silver 8 and the PSB Imgaine Ts to me is partially driven by your receiver. The Monitor Audio Silver 8s require a minimum 80w of power and if I recall, you have 4 speakers in a woodshop. You can't drive the Monitor Audio Silver 8s with that NAD receiver. This leaves you the Kefs and the PSB Imagine Ts as units that you can drive well.

Between those two, it is a matter of personal taste. I like the PSBs because to me, they are smoother and more natural sounding than the Kefs. I find the Kefs sound a hair grainy which I dislike. It sounds similar to the B&W 68x line which I also dislike but the important thing here is that I dislike it and your may feel free to disagree. Considering that the Imagine's are $400 more per pair, I would do my best to spend some time listening to both if you can before you purchase.

Your other choices are outstanding IMO.

Check out the Kef dealer locator. Then call the retailers to see if they have the Q900s to listen too before you make the trip.