It's difficult to find Carry-on luggage in the US that meets the European standards for size. The main problem is the height. The American standard says "22 inch", and European standard is 55 cm or 21.6". I also am really careful about weight, because that is often more restrictive than the volumn.
I just got back from Europe. If you look at luggage there, in the airports and, perhaps in town, the sizes conform more to the European standards. Though, how to you buy one there. I guess that you could purchase one and then check the one you came with for the trip home. OR... maybe you could take your stuff in a cheap throwaway duffle, and then transfer to the new one once in Europe. Hmmm. Has anyone tried anything like that?