If I understand your description, it's not going to be as easy as picking a shrub that will grow in your zone. The west/southwest aspect is usually a tough one when your planting against a building.
Then with trees casting shade later in the day you will need to plant something shade tolerant. And the problem with that is that it sounds like it will catch sun at a hot time of day, plus the reflected heat from the house wall. Most shade plants that can take a few hours of sun do best with morning sun, when the day is still relatively cool.
Also your clay soil is a concern being under the drip line of your house. You will need something that can take wet feet.
Off the top of my head, yews are tough enough to grow in those conditions, but they aren't showy, flowering or fragrant. (Barberry aren't fragrant either btw.) Their are a few golden tipped yews that are different from the usual dark green ones.
Well, I just went to your site (nice!) which I should have done before shooting my mouth off, and they say that Viburnum davidii will take a western aspect. I can vouch for their beauty. I would plant one in my border for sure, but the ones I'm familiar with get pretty large. They also have it in the clay soil category, which I'm skeptical of, but maybe...
I have a personal loathing of thorned plants and barberry and pyracantha can be painful to work around. There are a lot of different sizes that pyracanthas come in, ground covers to large shrubs.
Mahonia is prickly too, but evergreen, deer resistant, (actually nearly deer proof, unless you have a lot of deer pressure and they are very hungry) has bright spring blooms, and a nice fall russeting of a portion of the leaves, so I think it's a good candidate. It's also tough as nails.
I like that site you found, I'll have to do more exploring there.
