11" 1.6 Core2Duo Macbook Air for $450?

I need a laptop, badly.

I have a deadline in a month so the hope to wait until WWDC has peacefully fluttered away. I am fully aware of the approaching Retina Macbook Air, but it's looking like that has been pushed back to September or October, after the summer days in coffee shops and, more importantly, after this deadline.

I found an excellent condition 11" Macbook air with 4GB of RAM and 128GB SSD. The reason I'm tempted is because I live in OS X. I know Windows and know it well, but I deal with a lot of HLS+ partitioned drives as a DIT (digital imaging technician) and spend hours using rsync each day to have some need for a unix based system. I was enticed by Chromebooks, but I live in the depths of the NYC subway for a couple hours each day so I need offline capability and, more importantly, ability to use Final Draft and Office.

I think the dream would be a $450 13" but I am not sure. I need to read HLS+ drives, use Final Draft, and portable and small enough to carry around in a bag all day. If you were pressed for time, what system would you get? I should also mention I have a very powerful Mac Pro at home so any video editing or heavy lifting will always be done with that. This would just be there for when I am out in the field or running about my day.

Thanks!