I would like to use a white/bianca carrara marble subway tile for the backsplash in my kitchen.

I am looking for feedback on using marble as a backsplash. I've been told it needs to be sealed. Is this easy to do and how well does it protect from stains? Would marble be a big problem behind the sink with water splashing up or behind the stove (the stove has about a 1 foot high panel on the back)?

Can anyone recommend porcelain tiles or other material that looks just like marble without looking fake?

A last option is to use porcelain white subway tiles. I am trying for a timeless look that won't look dated in several years.

Also what size would be best, 2x4, 3x6? The distance from counter to cabinets is only 13".