I would strongly encourage you to get standard-sized appliances, especially for ones that slot into a specific space like a dishwasher.
We recently needed to buy a new refrigerator. Our opening could not take a standard 36" French door fridge - or must be either a single-door 36" or a French door 33". Neither of those are the current standard. While on the surface there are several models that could work in this space, it quickly became clear that we have virtually no options. Fancy ice maker? Not available. Door-in-door? Nope! Multiple interior layout options? Hah, no!
It turns out that companies only make significant options in the most common size. Thinking that you do not care about those options? I believe that you do not want them now. That may well change in the future, and then you will be stuck. A family’s needs change as everyone ages, and the things that feel great now may not be good choices for you later. Flexibility is king when it comes to long term planning.