Don't - this is a better space for a peninsula. Any Island in this space must be tiny and can't be sat at. Unlike a peninsula. An island would just clog up your kitchen. We find that many of our customers think they want an Island, but what they really want is the best looking and functioning kitchen. An island in a room this size eliminates the possibility of a great design. I would first get professional help. Often initial help is free. And if you decide on putting something in the middle of the room make it movable. Like a butcher block table.

Option 4. I would not have more than 2 different cabinet finishes. Darker, grounded look for the base and island, with lighter, airier look for the uppers would balance the room.

Hi, this is parveez from best interiors , island type of kitchen , it will look good but the combination should be a light one in colour thn it sounds good

Totally doable as long as the island is not too bulky. And of course if the circulation space around the island is at least 3'-0" wide. You don't need too much space to move around in a kitchen because you should be able to pick up a hot dish and put it down on another surface without having to move too much. 12'x14' is a large size and a work island would possibly make the space more practical to use. In the pictures attached, the work island is only 2' wide but 4' feet long