As I have said on occasion, appliances fit cabinets. Dishwashers fit a base 24 inch cabinet, so consequently dishwashers are all 23.75 inches wide. Somebody should tell Dacor as their dishwashers are 24 and 30 inches wide and are for new construction only.
There are three options for 18 cabinets. All of which are surprisingly good.
Frigidaire is a basic dishwasher with decent cycles.
Miele is an exceptionally good dishwasher with a stainless tank, quiet operation and unsurpassed product quality(quality means great repair record). Then again at roughly $1200, it should be
The sleeper pick is GE monogram. Stainless tank and decent features, but is half the price of the Miele
An interesting alternative is the Danby countertop dishwasher...A product without cabinet requirements