The range hood should suit your type of cooking and should vent to the outside. If you do a lot of fast frying or wok cooking then to avoid a fire it must vent directly outside.
It is best to have a preparation space on either side of the sink and the cooktop.
A wall oven should be positioned at the correct height for easy access.
The microwave can be positioned above the wall oven, with a pot drawer underneath and perhaps a small set of cupboards above.
An under-cooktop oven is positioned at a lower level than a wall oven but it is often a more efficient use of kitchen space.
The style, materials and finish of the doors and bench top are important, as they are not easily replaced.
Some extras to consider:
Built-in appliances should be reliable, quality brand names, so that they last for many years. Replacing appliances can not only be expensive but also cause major problems when the new appliance is not a neat fit in the original opening.
The food that you eat and way that you cook it is important to your health. The materials on which you prepare food are also important for your health so when considering surface finishes try to choose natural materials and finishes which are low in VOC's (Volatile Organic Compounds) such as timber, granite, marble, bamboo and ceramic.
For more information on appliances and kitchens look in the interiors section under Kitchens.