If you combine finishes, I'd rather see brass and nickel combined on each element. Note the mirrors below have some brass trim but combined with mercury glass frame.

Go with chrome. Always chrome. Chrome is the standard for a reason. When you need to replace something down the road, chrome is chrome, and it'll match.

Second on Theresa's suggestion. Chrome will always be readily available to easily match for future replacements

@CAGE Design Build and @Theresa Peterson

Thank you. Are you suggestion chrome and ONLY chrome?

Brass and nickel together are a warmer tone. Brass shower replacement will be harder to find in future possibly.

I'd select polished nickel before chrome if the budget allows.

Polished chrome offers a cool, bright, bluish-silver, highly durable, and easy-to-clean finish ideal for modern, high-traffic bathrooms. Conversely, polished nickel has a warmer, softer, slightly yellow or golden tone that feels more traditional or luxurious, but it is less durable and requires more frequent maintenance to prevent tarnishing.

I like your choices. I would tile the whole outside of the pony wall. Paint the walls white.

I would consider white shower wall tile with soft beige travertine shower floor. White threshold. We did and it's a nice look and in this case white tile for the pony wall.

Similar to this:

Recommend an outlet at the toilet for a powered bidet seat (warm seat and warm water), and a fan/heater combo for the exhaust fan and light.

How are the doors of shower opening? Sliding? Hinge?

I am unable to edit ~ I see.from your inspiration board they will be sliding. Hooks near the opening would be best for towels since you have a pony wall. The towel bar near sink ~ if that’s for bath towels are you able to install them heated? Might be a nice touch.

What you have is a mix of cool and warm colors that are now crying out for the same mix for metal and IMO that will add to the mess . IMO do chrome to keep it simple since most of what you see is the vanity in blue and white I do not think brass is a good choice there. I do not like mixing metals as a rule.

I love mixing metals. I am renovating my bathroom. Attached is a photo that AI adjusted with the colors I am using. The sink faucets and all fixtures are polished nickel. Light fixtures and knobs are brass.

I love mixing metals. I am renovating my bathroom. Attached is a photo that has the color tiles and vanity as well as the same tiles I am using.

All fixtures will be polished nickel and the light fixtures and knobs will be brass.

Also you only need one light in the shower in the center.

I used polished nickel and satin brass together in my master bath. As others have said, they are both warm metals so they work well together. Chrome is a cool metal that I personally wouldn’t choose. It’s been over 10 years and I have never changed out anything.

I agree with the other posters that mixing metals might work out well if they are all either warm tones or cool tones. Mixing warm and cool is just asking them to fight each other.

I don’t know why you are afraid to use only one metal. I would. Stick to the brass.