You might also try to fit the Trophy inner pannier bags if you can find them. I had them and they were not necessary as the bags came off easily as luggage. They were nylon like material and fit perfectly. They did make it easier to get stuff into hotels as they didn't clank into the walls and wouldn't get scratched. They went with the trophy when I sold it. also the Sprint had inner bags.
Before I went in for the bags in found a near fit back pack at REI (camping retailer) and it worked well. They still have too many sizes that might fit.