I agree with everyone's assessment that this is not a good space for a hybrid tea rose unless you can find Silver Jubilee. I do think selections from the Fairy Tail line might be good. One of the more vigorous roses I've planted is Caramella FT and it seems to pretty resistant to black spot; but mine in its third year is nearly four feet across. If I had not failed twice with Icebergs in NJ, I'd recommend them, too.
In a space this size, I think one might consider polyanthas or even some minis as well as compact floribundas. The polyantha Marie Pavie grows between knee and waist high. And Katherina Ziemet probably tops out around knee high. Polyanthas are likely to be able to remain healthy and bloom in a little more shade than even some floribundas. Gourmet Popcorn might be fun. It could absolutely be trained as a hedge to any height between knee and waist (for a shortish person). It did well for me in NJ. I know all of these flowers are white which may sound boring... but white pops in shady spaces.
One might consider planting The Fairy in the middle (or Jeanne Lajoie) and training into a fountain shape, then planting four Gourmet Popcorns in the corners. That seems like a fun design for the space. It also uses roses that are likely to do well in it. Other minis worthy of consideration might be Cupcake and Winsome. Either hybrid musk Felicity or Ballerina, or either alba Queen of Denmark or The Alexandra Rose might also look good in the center of such a design, though any of these four would require some annual pruning to keep them in bounds. I grew Felicity, QoD and TAR when I lived in central NJ and all three were totally awesome as shrubs topping out around four or five feet in height. Ballerina made it to six or seven. Though the two albas QoD and TAR bloom just once a year, but they bore more blossoms in a season than any HT did for me in a decade there.
In brighter colors one could put Red Cascade at the center and Rise 'n' Shine at the corners.
Check out all these roses at HelpMeFind.com. All are in commerce, I believe: try Antique Rose Emporium for the minis and polyanthas and David Austin Roses for the albas. Whatever you decide, please do send photos when it's done.
