I agree with chipz, the MacBook Air would be best. Judging from your workflow, however, I'd suggest one of the refurb models in the Apple Store. I'd predict the 13-inch version ($929) as being best for you, but if not there's also the 11-inch available ($849). They come with the same 1-year warranty as new units and should fit your workflow well for a good price.
7/2/12 at 12:08pm