Here are some more ideas for your kitchen island.
Decide what you’d like to use the island for. Some of this will be determined by the space available. If there’s only enough room for a 3 ft. square cabinet, you may not want to consider a cooking surface, since you need some counter space next to elements. If you have room for a large island, you can incorporate a stovetop, a sink, and counter space. Remember that if you are cooking, you should plan for a range hood above the island.
Adding an extra sink can be a great bonus in the kitchen. Even if you already have a double sink, you can speed up the work with a sink in another location (and a helping pair of hands to go with it.) Of course that means new water supply and a new drainage system. With an island in the middle of the room, you may find it tough to have a drainage vent as close to the trap as the code requires. In this case, a device called an air admittance valve will be needed. This performs the job of an air vent, without the need to extend the pipe through the roof. The valve sits on top of a length of vertical pipe inside the island; it allows air in when needed and shuts when not in use, to keep sewer gases from getting into the room.
When it comes to design, your options are wide open. At the most simple level, you could purchase a couple of cupboard carcasses, add doors and drop on a counter top. Or you could plan something that truly looks like a piece of furniture; just make sure you top it with a durable counter surface, finish or butcher block.