MacBook for developing an Ipad 4 game

[Tomato]

I would like to make games for the iPad 4. In order to utilize the full resolution of its Retina display, I will ideally need a Mac with an equally good or better resolution. My best choice seems to be a MacBook Pro with Retina display, which gives me the horizontal and vertical resolution I need. I also want to be able to make games to the full power of the iPad 4. There is a $1699 Macbook Pro with a 2.5GHz Core i5 and Intel HD 4000 integrated graphics. Would such a system be as powerful for games as the iPad 4, capable of utilizing shaders as well? What I'm worried about primarily is the graphics processing power of that MacBook. Or do I need to go all the way to $2199 for a Core i7 and the pretty nice Geforce GT 650M?

I'm trying to match or top the power of the iPad 4 for my development Macbook.