There are some blueberry plants that get that tall.

Is there enough sun for pole beans or scarlet runner beans? They would only need a few strings which you could run down from the top of your porch. If you don't like picking beans all the time, you could grow a variety that's good for dry beans and just pick them all in fall.

Grapes. I have four front windows with Thompson, Flame, Fantasy, and Concord seedless in front of them and they give me good privacy. I didn't install trellises, I use twine which blends in quickly.
John

do you want something for summer only, then try pole beans.
hops will grow very quickly as well, come back every year
but die down in the fall. what about a hardy kiwi vine or hardy passion fruit?
diggerb

An asparagus row takes a year or two to establish, but once in makes a very pretty, ferny, minimal care screen that will return every year. You can cut it to the ground in the winter for a neat look. It's great for attracting pollinators, too.

I'll second Josie's vote for blueberries, too. Many types will give you great red fall color as an added bonus.

Both of these would need plenty of sun.