What should I put between two "glowing embers" hydrangeas?

I have a 15' x 6' rectangle under my big bay window. I already got the two hydrangeas and I want to put a sweetspire between them, but it's going to get too wide. What other shrub/ bush/ hedge can I use to fill in that space that will attract hummingbirds and be about the same 6' tall fully grown. I have two blue bleeding hearts with a black lace between them in a "L" shape on the other side of the porch. I live in zone 5a. Glowing Embers are a pinkish-purplish color with green foliage.