If you are going to try roses with only 4 hours of sun, you will want to go with lighter colored roses. White, pastel colors, pink, peach, yellow. I've read that they do best in area's with less than 6 hours of sun. It's still not a premium spot for roses...but the lighter colors will do you best.
This sounds like the perfect spot for Arabian Jasmine to me, it would make your courtyard smell nice as well. AJ can handle the hottest part of the day without burning, and would provide awesome evening fragrance. Just a thought :)
alan
