I would never do tile or porcelain in a kitchen. Its too hard on your legs-especially if you like to spend a lot of time standing up cooking or baking. WAY too hard on the legs.

I have tile in my entire home and absolutely love it. It is only hard on the legs if you stand all day long, which in a home owners case would not necessarily happen.
Tile is so easy to keep up . No, I have joint issues and the tile is not a problem. Just from experience.

I am getting white cabinets and bianca carrara counters and my floor (which is the only thing finished) is travertine herringbone.

The trav does have warm tones but the grey and white carrara sample I have looks surprisingly good with the "Noce" travertine that has a high V number (amount of variation between the different 3" by 6" tiles.)

My floors are Italian porcelain look alike travertine on a diag. Just renovated kitchen with whit raised panel cabs, very mild sienna bordeaux granite and am getting ready to install backsplash. I've settled after months and looking and looking for a brick subway bottincino with very mild coloration. It really goes well with the floor and plays up the granite nicely. It looks great with the tile floors! I'm in love!

It's always good to be 'in love' with your choices! It sounds like your hard work is paying off! (: