Hydrangeas are wonderful.. huge lush, long lived, super easy to root from cuttings, shade loving, and as long as you cut green stem they last nearly forever in a vase. if you don't have any, get some... preferably free from a neighbor. They are that easy to root from cutting.
You already have peony, which are my
favorite
Any bulb lily cuts beautifully and is long lasting. you've already been warned about removing pesky stamens to avoid stains, but you only get one shot per year. Oriental lilies have the most beautiful smell, so it's worth it for me,. Just like hyacinth and tulip, you only get one per year But lilies are better. If they have loose soil and full sun I've had single stems fatter than my thumb with 20 blooms... like peony, either steak them or cut them early, because heavy rain can knock them over and cause a lot of damage to delicate petals, to say nothing of the slugs that will feast on them overnight in wet weather
I love, love oriental poppies. They bloom early and last long in a vase. Their big blooms of papery petals on long delicate stems w the most outrageous orange/red around either blinding yellow or jet black centers- it stops me in my tracks every year.
Next fav is delphiniums, if you like snaps, you will love delphinium. They do well as cut flowers, and will reward you with more blooms when you do cut, but they are not very long lived as far as perennials go. They don't like hot weather, so if you plant do it early to make sure they have plenty of cool spring to establish deep roots in cool damp soil before they bake in July.
As a final note, Because I could go on forever, I think if you have the right vase, all flowers are cut flowers. Snaps are not perennial in 5b,
but still beautiful, and cutting them will encourage more blooms outside, unlike you're "one and done" bulbs. As far as annuals, verbena, geraniums are lovely in a short vase and I often float a short fat clematis flower or begonia bloom in a martini glass on the bathroom vanity. You don't need a long stem to enjoy cut flowers, you just need the right container.
