In general, Buck roses aren't all that hardy. There are a few exceptions, like Applejack, but most are just crown hardy here. Disease resistance also isn't reliable. Hawkeye Belle had horrible problems with blackspot. Country Dancer is reasonably healthy, but less than 2 ft tall after about 7 years.

Parkland roses are also problematic for blackspot. They are from a cold but dry prairie climate, and often struggle in the east. Morden Centennial was asked to leave at the same time as Hawkeye Belle, and for the same reason.

Quadra is new last year, so it's hard to say what the final size and shape will be. Get it grafted. It doesn't seem to want to grow own-root. Seafoam looks to grow about 6 ft canes. Whether that is long enough for what you want, I don't know.

The trick with the new trellis is going to be finding a rose the right size. A monster will eat the gate, a wimp won't do much of anything. My Quadra is in a similar situation, and I'm hoping it doesn't outgrow the spot. Captain Samuel Holland is exactly the right rose, but it's down the row a bit and I don't feel like moving it. John Davis is another possibility, and maybe Clair Matin.

hmmm... i was considering a rose called "america" to plant on either side of a trellis. does this do well? or would someone recommend another that does well up here and repeats well? i'd like it to be lush and look "overgrown".