You could put clip-on aerobars on to the bikes you have now to be able to crouch out of the wind. I know some people have said not to bother upgrading, because you won't notice much speed difference. But if you notice an enjoyment difference, that's definitely worth it! Its good to have commuter bikes that make you smile. I'd test ride everything in your price range and see what feels good. (and can hopefully accomodate racks and fenders)