I don't know where you are, but often best results come from local lenders. In forum times past, PenFed FCU got raves for their mortgage rates, but I haven't seen them mentioned much lately, so that may have changed. Anybody know?
Are you sure you want to lock yourself into ARMs that could all reset at the same time? For tax purposes, you might want to stagger the sales over a number of years. Why potentially put yourself at the mercy of fluctuating rates?