(Usually I carry two laptops when I travel. But it’s a very heavy thing to do. I

(Usually I carry two laptops when I travel. But it’s a very heavy thing to do. I am considering getting an iPad and the software to use it as an external monitor. But it’s like 600 bucks plus the software, cover and stand, and a keyboard if I want one. Whereas another Macbook Air(not retina), new Macbook (retina), or Macbook pro 13″ retina is only another 1000-1400. I am very down on the new macbooks – they’re really expensive and have only one port. So they’re a no-go. Not sure what I should do. Advice welcome. Thanks.)