I would say, get the cheapest one in terms of storage space and buy an external hard drive to save you paying through your nose for a larger drive in the Mac. They are quick but they're only really useful for booting up and large programs like video and photo editing software. Files are better off stored on an external hard drive. And it also means you can take all your file with you without bringing your laptop everywhere.
Also, if the CD/DVD drive is a must, then you should probably look somewhere else or buy an external one which can be quite expensive but that is the way it is going with tech trends now.
Also, the latest rMBP are so much lighter and thinner, only slightly larger than the current MBA at its thickest point (18mm in rMBP compared to 17mm in MBA) so portability with a Mac is true for both, but the Air is definitely ultra portable.
If battery life is a problem, the Air is probably better but you do lose a bit of performance for an extra 3 hours supposed battery life (9hrs with the rMBP vs 12 hours with the MBA).
Finally, there have been talks of an updated MBA so if you can, you could wait but its not really a must. My opinion would be to get the rMBP, I feel it offers more performance compared to the Air for a package, not that much bigger.
Also, you may want to look at the Surface Pro 3. Portability to performance ratio is probably the best here, but you do lose OSX and also USB ports, however you can easily buy a cheap 7 port USB 3 hub from Amazon for next to nothing. Just consider your options from both Windows and Mac.