Pinky Winky is a fun plant, but mine is 8' tall x12' wide, so I think is out of the running for you, but if you want more info on it, I'll add more, including a photo.

I love Quickfire - it's one of my favorite garden plants and without a doubt my favorite paniculata, though it isn't necessarily to everyone's taste. I really like the lacier blooms on paniculatas rather than the huge and super full ones, so if you prefer the more voluptuous ones, QF may not be for you. Its panicles are more oval and less cone-shaped than most, and large, but not enormous. Mine is in bloom from the last week in June until hard frost and progresses from bright white through salmon pink to a deep cherry pink. For me, QF is about 6' in all directions and has been about the same size for the last few years. The branches are stiff enough so that the panicles are always held up and it's a great scaffold for a clematis. The leaves turn a bit gold in the fall, but aren't spectacularly colored. I like leaving the dried blossoms on for the winter and then most years prune them off in early spring, though didn't get to it this year.

QF with Clematis Little Bas in early July

QF in August

QF in fall