Was going to add that currently there seems to be plenty of white available since its currently “in”. And you don’t have to replace all at once. No one cares if yours are mismatched until you are ready to sell. IMO stainless is more universal.
Are your stove/microwave one unit? Built in? There are some great options for microwaves that also function as ultima cook and convection. Very handy. Are you getting gas or induction? And as for brands, there are plenty of good quality brands. Whirlpool makes/owns Maytag, JennAir, KitchenAid, Amana, etc. GE makes GE profile, Cafe, and the parent company also owns Haier, and in the US, Hotpoint.