Aktchi gives excellent advice, as usual. ^
DSH, I totally see your point. If you have a camera bag already you want a roller so you can transport both easily. Makes sense. In that case, do go with the 19" Travelpro Plat5. I am a bit partial to this particular line (not the brand) because I own their 22 inch model and love the thing to death. It is important to know that their warranty on this line is basically the same as the BR warranty. Check their website.
The 19" model will fit the sizer and when you expand it is almost as roomy as the 22 incher. BUT if the sizer folks are strict, the expanded version won't fly because it is too deep for the sizer when expanded. Still, you can say that it is under 45 linear inches.
Some of the ebags reviews for this particular model are negative. WHile I don't own this exact model, I think their criticism is transferable to the one I do own and I don't agree with what they say e.g. flimsy handle and also repair cost. He might talk about shipping cost but repair is free under warranty.
Till