I don't know what would work in your zone to be honest, but do have a look at burgundy iceberg. It does well in cooler regions. Though not red, it's a dazzling beauty.

H

Lavaglut is a beautiful dark red, cold hardy, great repeat bloomer.

I think Drop Dead Red is a very good red floribunda, has been disease resistant for me on a uniform bush and repeats quickly. Tom Carruth seems to have some really good roses. Regan's Nursery said it is hardy to Zone 5 and I think it is readily available. Pictured here is its first flush.