I begin a Graphic Design course in September, and want to purchase an iMac and hard drive in advance. The thing is, I just don't know where to start - the only Apple products I have ever owned are the iPad 2 and iPhone. Would a 21.5 inch with 1920 x 1080 resolution, and 8GB be enough? This is obviously the cheapest option, and i am most probably going to have to invest in better for long term usage. Obviously,it will need to be enough to run Adobe creative suite etc. I'm also interested in whether it is worth buying refurbished from Apple? Any other pointers would be great.