Look on AJ Madison because they have a good search capability. They carry a range of small appliances from 18" wide DW of varying price and quality to 24" wide ranges to apartment size refrigerators.

You can go from inexpensive and very basic to expensive European or American brands. There isn't a whole lot right in the middle price wise in these sizes.

You might have some luck with Miele. They make a good quality 18" wide DW, a 24" wide oven that's a combi of steam, convection and broiling, and cooktop units as narrow as 12".

I've used- bosch and miele 18" dishwashers;
Leibherr and summit 24" fridges;
Viking, summit, avanit 24" gas ranges- bluestar also offers a 24 but haven't used it.
No major issues in the limited cross section of folks I've dealt with. The Leibherr install can be fussy.