I personally prefer white sand as it gives more contrast to fish and coral, but there are some gorgeous tanks with black sand as well. Guess think about stocking and how it would look against a darker canvass in a way. I’d recommend getting larger grain sand, special grade pink I believe - shop around as price differences are pretty significant. Finer sand may look a bit nicer but is generally pain when you add in almost any amount of flow.
For most of my tanks I’ve used live Fiji rocks but they’re getting harder to come by. Pukani is probably the nicest looking IMO and provides great surface for bacteria to colonize. It’s also a phosphate factory so make sure to cure it before putting in tank.
Another option that I recently saw at reefapalooza and looks really cool is two little fishies Stax rock. Whatever you pick I’m sure will look great!