For every new kernel that comes out, you will need kernel patches and mods to support AMD. That said, you'll never be able to use a clean ("vanilla") fresh install without always having to add the AMD hacks first. Currently, AFAIK, there's no Mac hardware that uses AMD processors (correct me if I'm wrong), so if you want a system that closely emulates a real Mac, you'd be much better off with an Intel Core 2 Quad on an Intel-based Gigabyte board.
You'd even find readily made custom DSDTs and BIOS patches for Gigabyte boards over here:
http://www.efixusers.com/showthread.php?t=38Still, I understand your initial point, and I won't talk you off from buying AMD. It's your personal choice, even though you're making your life a lot harder. More work and hassle, more waiting for the right mods to come out (after every kernel update), a higher risk of incompatibile mods, more chances to fail, but hell, why not, it's a challenge!
It should be doable, and the rest of your hardware looks quite allrighty.
My desktop system is AMD + nForce + nVidia, but I didn't dare trying to convert it to a h*ckintosh yet. Instead, I did it with my Core 2 Duo laptop, which is a highly similar in specs to some MacBook Pros. And as such, it works pretty nicely as a Hac. Good luck, and don't forget to come back with your results! I'm curious on how it turns out, eventually.