How Powerful of Mac required for iOS developement

Hello, I have looked through the answers and Unity's website and I know that Snow Leopard is required for Mac developement. Yet, I was wondering how powerful of a machine is actually needed? Is a Mac mini suitable? Core 5 or 7? Does it make a difference? I would still be creating the app and testing it on windows with android, but to put it in the AppStore I need a Mac, so I'm guessing I would not need a super powerful Mac? Thanks to anyone for your help and suggestions