I think David Austin roses - especially those produced with and after the introduction of Graham Thomas, Heritage, and Gertrude Jeckyll onward - are great choices for rose gardens in the NE. Golden Celebration might need some protection from black spot, but many are just about flawless. I'm a great fan of Tess of the d'Ubervilles, Eglanyne, Abe Darby and Graham Thomas.
I'm a great fan of Palatine roses, also. I've also had great luck with roses purchased from David Austin Roses (USA). The plants tend to be big and healthy. I've gotten plants with main trunks more than two inches across from there - unheard of from any other supplier. Another advantage of this source is that they will have a greater selection of newer DA roses as well as a good selection of older ones. For older DA selections grown on their own roots you might try Chamblees.
When I grew roses in NJ zone 6b I also had really good luck with roses from Antique Rose Emporium. Not too many DA roses, but the roses they do have are healthy, vigorous, and pretty resistant to disease. I was especially pleased with Felicia. It's a hybrid musk that gets nicely shrubby and is really care free. This year I discovered Caldwell pink which grows vigorously, is very nicely branched, has flowers with a nice little button eye, and repeats almost continuously. It also had red foliage in my garden this fall.
Other roses that pleased me when I grew them in NJ:
Electron and Midas Touch were just about the only HTs that worked for me. I know it's a cliche, but I was very happy with New Dawn planted on the south facing wall of a garage. Even though it bloomed once, I was very pleased with the alba Konigen von Danemark, sold by DA roses as Queen of Denmark. People who grow roses in California may not be very pleased by it, but I found Knockout to be a rose of amazing vigor and a model of good health. It looked good planted with Sally Holmes, some iris, and a few pink peonies. If its roots were kept moist it was even slightly fragrant. Madame Plantier looked really good until it got a slight whiff of Roundup over-spray and died instantly. Finally, I found most of the Canadian Explorer roses to do well: Champlain, Henry Kelsey, John Davis, Alexander McKenzie. They lack the fragrance and refinement of DA roses, but they can be real workhorses when it comes to producing bloom.
Good Luck.
