If I book the cheapest award ticket, the economy milesaver off peak for a flight to hawaii, can I still pick my seat? Is says it is subject to capacity control, which I am not familiar with.

Does my status (PLT) help me at all with this?

I am a big guy and need the extra leg room. If I cant do this, I suppose I will go with the Business/First MileSAAver award. Will this get me into first class?