I have calacatta caldia slab and tile in my kitchen. I got it at Arena Stone in northern NJ. They specialize in white marbles.

I have seen some variation in calacatta tile depending on the stores I have gone to, and they all call it calacatta or calacatta gold. You may just want to look around and see if you find something you like that pairs well with your slab. The tile will never be a 100% match to your slab anyway.

We are in the process of remodeling our master bath and will be installing calacatta on the counter, floors and as an accent tile in our shower niche...rest of the shower will be white subway.

We are also planning on putting calacatta in our hall guest/family bath with the calacatta on the tub/shower surround and on the walls chair rail height. Floors are going to be a wood porcelain tile and the countertop will be a quartz.

I think it looks good to break up the marble with another stone/texture....as long as it doesn't get too busy.

We got marble (White Thassos) for our bathrooms at K&K Marble on Long Island, NY. I think they have a good selection of different types of marble, so it might be worth calling or visiting them.

FWIW, if you do end up going with White Thassos, we have it in all three bathrooms' niches, and as trim tile in one bathroom, and it's just as white today as it was 3 years ago, when it was installed. I sealed it using STT's SB Sealer.

Here is a link that might be useful: K&K Marble Importers

Thanks, all. I am on the hunt today for some tile, perhaps Caldia as it seems close! Wondering if you all have heard of Glassos...a man-made Thassos look-alike that is 1/2 the price and beautiful. I am thinking of that for the shower as it has the depth that porcelain tile does not.
Can't wait to be done!