Check your soil PH if possible before planting; they need acid soil and do take a few years to produce berries. You will need a few varieties to get fruit, for cross pollination.
A mulch of wood chips will decrease the soil Ph( make it acid). The good thing about wood chips is they are free from any tree guy, just call and ask them if they want to dump them, as close as they can to the slope. The birds will love it, the fall colors of the leaves are ornamental.
Planting a variety of plants on you slope is important as well.
Sounds like a great plan..
Cherry

I dunno know, I thought blueberries needed moist, well drained soil. If grass isn't growing well there, I'm not sure blueberries would do well on the slope - maybe at the bottom assuming it doesn't collect water there. But I've never grown them so I can't really say.