one thing which may be an option and cost a lot less than either of the options discussed is finding a really good boot fitter and having them fit a boot for your wife, strolz is a good [if somewhat old style looking] option if you want a shell specifiaclly for your foot width and you want it in black black or black but if you look at what a boot fitter does they select a shell from a range of boots narrow ones medium ones wide ones high inspet, low instep wide heel narrow heel etc etc. if the shell is correct then the need for a foam liner may be reduced, ..... a good fitter should be able to take the closest shell to her foot and make some modifications to that shell, the liner is then just the interface between the foot and the shell, often foam is used where the shell selection is not right, it is the correct liner for some but not all. you mentioned that she is sensitive to the cold, foam would not be my first choice for a client presenting with this type of problem
how much skiing does she do in a season? does she ski hard? what sort of level does she ski at? these are all things which may need to be considered, for a warmer liner then prehaps the intuition, i she suffers from not being able to get a boot tight around the heel then prehaps a zip fit liner, both are more forgiving than the foam and warmer.....
the list of fitters at the top of the boot guys forum should give you a good fitter in or around your area, spend time with that fitter and get your wife the best boots she has ever had, buying into a system may be the right thing to do on the other hand it might not be.