So my sister wants to move to mac but can't really afford a Mac, plus she already has a PC.

This is the Spec
Fatal1ty F-I90HD - Mobo
Intel E6300 (core2duo)
2 gig of Ram (can't remember brand, maybe corsair)
Onboard video from Mobo.
Creative soundcard (not actually needed though)
Samsung 500gb HDD

So how much of this can stay the same, and what is needed to change to most stable hackintosh, can someone explain the process as well as I don't understand.