What is your planting zone? That can make a big difference as to which plant/s would be suitable.

Climbing vines interspersed with some columnar evergreens? Put some curve/s into the front edge of the bed for visual interest. 7' wide is enough space to have a bird bath and/or feeders; or a small arbor (maybe with a grape vine growing over the top?) with a comfortable seat and a few pretty pavers to keep your shoes clean even when all else is muddy. Clematis suitable for many zones, comes in a good choice of colors and heights, different varieties bloom at different times of the season, and it is comparatively trouble free - but be sure to label *securely* as to which pruning group each plant requires (says one who lost several labels and now has no idea which red clematis prefers fall pruning and which prefers a severe winter clip).

I have to suggest the moonflower vine. When I grew it on a trellis at the front of my house it went crazy. The vines went up the twine I hung the trellis with and then started up the roof. The blooms are huge too on the moonflower. I suggest any vine from the morning glory family