Macbook Air (mid-2013) - 13 inch for Design & Development

I'm a web designer and developer. I'm planning to buy the new Macbook Air (mid-2013) - 13 inch. I'll be using Adobe Photoshop and Illustrator CS6 sometimes for light design work. And, i will upgrade the MBA to the highest specs, i.e ( i7, 8gb ram and 512gb flash storage ) I don't have any other computer of my own. This will be my first. And, I'll also be coding Android and iOS apps and a lot of other programming. I will be making this my only computer. Also, is the 1440x900 resolution of the MBA good for designing. And, is the screen good enough? Will this model be fine for me, as I will be making it my only computer. I won't be buying a larger display for desigining purposes, as my main focus is towards mobile app development. This is my very first computer, so please I need honest suggestions.