Bear in mind though that the island does not have to be square and can be made of a strip of different kitchen cabinets if you'd like that to be longer too.
Of course making other kitchen designs is fine too, and you do not have to stick religiously to one of these suggestions. However by starting with one of them you will give yourself a good starting point from which to add more cabinets or make slight changes. Try drawing a few designs up on an A4 piece of paper and see how much space you have to play with then look at the website where you want to buy kitchen cabinets online or discuss with the kitchen cabinets store and find out what the dimensions are like and work these into your plan. You will then use the plan to dictate which kitchen cabinets you buy, and the cabinets available will likewise help you to choose which plan to create.