The front of my house faces due west, with about a 2' overhang underneath the eaves. There is a 12' section between the northwest corner and the walkway leading to my door that has proven very difficult for me to establish any plants in because it doesn't get much rain, and it can get very hot there from heat reflected off my concrete porch. Currently, I have a few volunteer Rose Campions (Silene coronaria) growing there, and some mint popping up until I pull it out.
I have been thinking of growing some prickly pears in that spot, with the hope of also getting some fruit to eat (I'm not a huge fan of the leaves). With the overhang and shade from a magnolia tree at the southwest corner of my house, they would be in shade until early afternoon, then a brief period of partial shade, followed by full sun for the remainder of afternoon and evening; perhaps six hours of direct sunlight per day near the summer solstice.
I live in Portland, Oregon (USDA zone 8b) where summers are typically warm and sunny, and the other seasons mild and wet.
Would that be enough sunlight for them? Is there a species or cultivar of prickly pear that would do well in that spot?