I'm considering buying a mac, either new or refurbished, but not sure which would be the ideal set up. I travel frequently, but sometimes need a machine with some power. I've got 2 options: 1. High End Macbook, 2.4 ghz, 4gb ram. 2. 1.8 ghz macbook air (HDD 80gb) and 2.6 ghz iMac, 20" Display, 4gb ram. Anybody have any advice on which set up to choose? ...note, im not too keen on the macbook pro's.