This beautiful white Country Road boys shirt works well as a casual shirt and with a suit. Price includes the pink tie (don't need to use this).
The actual shirt (and full photo credit) can be viewed here:
https://www.countryroad.co.nz/shop/child/teen-boys/shirts/60244087-100/White-Shirt.html
This shirt can be combined with the Zara suit (https://rent-my-stuff4.sharetribe.com/en/listings/884740-boys-wedding-suit-zara-size-6).