Another alternative is to have a custom island designed just for your needs. Kitchen design experts can help you come up with an island that will fit perfectly into your space and also have all of the components you really want to have. You can add a cooktop, a sink, or even a built-in microwave oven which can free up a lot of your counter space. Both a cooktop and a sink built into an island can help the cook become more a part of the festivities when you're entertaining if the island is used as a room divider between the kitchen and other living spaces.
Plan the height of your cabinet appropriately. Since most islands will have at least two stools or chairs pulled up to the surface, you may want to think about the seating or stools first. There are two kinds of bar stools with one being much higher than the other. Unless the island will be used primarily for family eating, there really are no hard and fast rules on height. It does not have to match the height of the kitchen cabinet, but often does. If it is not going to match it should be taller in most cases.
Why do this, since even stock plans cost you at least a couple of hundred dollars each? Because the right stock plans can save you tons of time and money if you have a talented architect. Most plans are at least partly modular these days, and often you can even order prefabricated sections pegged to a specific house plan.
For example, we have seen islands of concrete when the rest of the kitchen countertop is made of granite or another material. We have seen a black island used as a nice "dividing wall" to keep the kids away from a white kitchen.