Go by the width, most are 24". Be careful, some are slightly wider or narrower - I had to replumb the supply line because my new one was quite a bit deeper.
Bring a tape measure and check out the actual machine if you can. If the new one is a bit narrower, that's okay - a bit of a gap is no problem, and a larger one can be filled with a strip of melamine.
I can tell you most are the standard width of 24 inches. At least back in the 80's they were. lol. I doubt if it's changes much. Just to be safe though measure it yourself or jot down the make & model # and bring it with you to the store. The salesperson should be able to help. If not... go somewhere else.
There are some called "deep-tub" dishwashers, where the bottom of the dishwasher's bottom is closer to the floor, so fitting-in taller items is made somewhat easier. If it does not say on the tag, you can tell by opening the door, all the way down. Deep-tubs have doors that are no more than a few inches off the floor. Regular models have doors that are nearly a foot off the floor.
Sear's tall tub has height adjustable upper racks. 24" is standard while portable models and European & Asian models may vary.
Either plastic or stainless steel interior, avoids calcium built-up or food stain. Energy-star with gov. rebate. Up to 7 wash level for cleaner dishes. Heat option to keep dishes warm/dry, etc etc.
Not sure of '05 but '04 Consumer guide rates Sear models as best buy/durable. I'm shopping myself for 1st time, as friends/relative often drop by for dinner & video. I hate at the end of night, people start doing Goodtime's dishes. If they do the utensils, I expect them to clean the rest and stay the night.