Replacement for Sickly Pyracantha?

I have an espaliered, yellow berried Pyracantha which was a great plant for the first 10 or 15 years, but which has been steadily declining for about 5 years due to blackspot. Ive tried pruning hard to remove the sickest branches and open it up more, but it didn't seem to help. The plant still grows with (un)reasonable vigour, but it produces almost no berries, and those it has are rather marked and not as bright and attractive as they used to be. The infected leaves, flowers, and berries fall to the ground in the adjacent perennial bed and it's virtually impossible to clean the area up enough to prevent re-infection. I've decided that without berries, it is no longer worth the substantial (and painful) effort it takes to keep this plant pruned, so I'd like to replace it.
Can anyone suggest a reasonably hardy evergreen shrub or vine which could be kept to about 5'-6' high and wide by about 12" to 18" deep. The area is part shade, but does get several hours of sun per day. The espalier frame is freestanding in the open, not against a wall so there is reasonable air circulation. One side of the espalier faces my neighbours' driveway and the other forms a backdrop to my mixed perennial bed. I assume it needs to be something which is resistant to blackspot, since thee will still be spores in the soil.
Would star jasmine work or is it too tender? Likewise Holboellia ? What other shrubs lend themselves to being espaliered and don't get too big or take up too much root-space? Are there deciduous plants I should be considering?