What's your waterproofing plan? Tile flange on the tub? Vinyl window?

That looks to be a kohler villager tub (right hand drain) with an integral flange. I think you've at least got that part of Sophie's concern covered. She makes a good point about checking with your contractor about waterproofing plans - there are many horror stories floating around Houzz about unfortunate homeowners who didn't do their homework

Sorry - my comment got cut off. I'm attaching a picture of the tub in our newly remodeled bathroom; same Kohler villager as yours. We used ceramic tile that resembles marble - from The Tile Shop, it's called calacatta creme matte and is available with many accessory pieces.

Also hoping that's a vinyl window - otherwise water problems:)

Yikes! Wrong picture! I'll try again: