A warning though, about the Retina MacBook Pros and MacBook Airs. If you foresee the need for more RAM or hard disk space, upgrade it when you order. These models do not have self-upgradable RAM, and the SSDs are custom builds. Some might call it the price of ever slimming computers, but it is a bit of a let down to not have the option to upgrade your computer.
The storage space can be somewhat made up for, via SD card. I supported a nifty KickStarter called, well
Nifty, which makes a Micro SD adaptor that sits flush with the body of all Mac SD card slot. Nothing's stopping you from using a standard SD, though it will stick out.