Given the width of your room, you really don't have space for an island or even a peninsula. Especially not since the traffic pattern goes through your work space. I think your best option may be to have a movable mini-island-- perhaps a butcher block. If the door to the kitchen were closer to the window end of the room, there'd be more possibilities.

What about something like this?

You can see how much more functional it could be if the door to the kitchen were moved over like this: