If you mean long stem roses. Those are probably hybrid tea roses not floribundas. You can get HT roses from a few companies. The will mail the roses to you at the time they should be planted. Usually they are shipped bareroot. What you will be looking for will be long stemmed roses with petal counts around 35. Shape urn, glossy leaves. Read up on how to care for them. Some nurseries do not sell direct to the public but through outlets so you have to get them there. Do not buy bareroot roses from box stores. The roots have been trimmed a lot to fit into the bags and the stores don't always care for the roses well. If you do get roses from them they are cheaper but you have to get them in the first two weeks after they arrive and before they break dormancy. You want grade 1 roots. Most will have 3-5 good canes. 1 1/2 grade roses are of poorer quality. They are cheaper, and they can grow but they are just not the best.
I prefer to get roses from companies that primarily are rose growers. They usually guarantee their roses and the roses come with an instruction pamphlet. Jackson and Perkins also has a rose hotline where you can get advice on the roses.
https://www.edmundsroses.com/dc.asp?c1=H ... +Roses&c=6
https://www.regannursery.com/roses/hybri ... oses.lasso
Weeks roses sell a lot of knockouts but do not sell directly but wholesale only.
my favorite HT
Miss All American Beauty, Peace, Chicago Peace, Queen Elizabeth, Snowfire, Scentimental, Red Masterpiece, White Masterpiece, Chrysler Imperial, Mr. Lincoln, First Prize, Pristine, Olympiad, Veteran's honor, Summer Fashion, Francis Meilland, Touch of Class, Promise, Electron, New Day, Neil Diamond (reminds me of scentimentalin color. Scentimental has better fragrance)
I like Sterling Silver, but it is not a large rose or a strong one, but it was the first of the lavender roses.
Some of these roses may not be available since they are older varieties but the classics will still be available.