Personally, I would recommend against ANY laptop for that kind of work. The screen is small, and the resolution low (just a little higher than 720p) which is fine for most things, but not graphics work. And if you use it on battery power, you'll probably be lucky to get 3 hours doing any kind of actual work.

If you want an Apple system, consider an iMac. The 21.5" models are at least 1080p, which will give you quite a bit more screen real estate.

I have some reservations about the iMac as well, since it will have the same limited upgrade potential as a MacBook Pro. But you will at least get a much bigger display to work with.

A Mac Pro is the only system I could really say I would recommend for this sort of thing, because it will have plenty of upgrade potential. Trouble is, the starting price is about twice your budget. The Mac Mini is likely going to be too underpowered and lacking any meaningful upgrade potential that you can perform on your own.

If you do get a MacBook Pro, I'd save up to get one of the 15" models that has the Core i5 CPUs in it. That would go a long ways to ensuring the system had a fighting chance to last more than about a year and a half in your program.

Whatever you get, if you plan to keep it more than a year, I would wholeheartedly recommend the AppleCare plan. Almost any repair on a MacBook Pro will run $500+ out of warranty, and the same goes for the iMac. The $250 or whatever you might spend on an AppleCare plan can easily pay for itself with a single repair. So factor that into your budget.

And just while I'm at it... I wouldn't recommend ANY laptop for a graphics program. Mac or PC, they're going to have the same basic shortcomings, and laptops usually have very little upgrade potential. I would strongly recommend you focus on desktop models. More power, you don't have to worry about the battery giving out on you after about a year, bigger screen, etc.

Laptops are good for light use on the go. They function well as short term replacements for a desktop system, but even so-called desktop replacement laptops often fall very short. The portability they offer comes at the expense of overall processing power and upgrade potential. If you want to get a laptop IN ADDITION to a desktop, that would be another story. But if you only plan to have one computer, make it a desktop. And be sure to figure out how long you'd like to keep the system, and get an extended manufacturer (not store) warranty for that duration. In Apple's case you don't get a choice, it's an additional 3 years or nothing, but other companies offer 2-4 years usually in 1 year increments. Even with desktop machines, one major system failure can more than pay for that warranty.