Try to get a nice deep counter especially if you are installing an espresso machine.
You put cups under the groups when you are making coffee but they cups are taken off when the milk or whatever is poured into the cup - it just makes life a bit easier if there is a space in front of the machine. Tampers, milk thermometers, chocolate shakers... They all take up space.
Obviously you don't want a great big heavy machine filled with water and steam under pressure and at 115-120 deg C perched on a bar just wide enough to accommodate the feet!