I can call anything shit, doesn't make it true does it
The one thing AMD has over nVidia is Mantle (read more in my sig Radeon thread), but we currently can't test it, the beta drivers should be out 'today' (they were delayed) so you can wait a few days for results (again the same Radeon thread from my sig).
You can check my sig what kind of system I have.
I would recommend i7 if you can afford it and if you don't plan to buy new PC for the next 4-6 years, but towards the end of that cycle you will most likely have to play games on medium settings. If you plan and can afford buying 1k euro PC every 2 years then i7 is not worth it.
My last PC lasted for 6 years (Core 2 duo E8600 + HD5570) and I bought it with 4gigs of RAM when the 'norm' was 2GB for that time.
For average guy the most challenging will be 212 EVO installation (CPU cooler), there are easier solutions if you don't feel confident.
Basicly building PC is cake if you ever played with Lego
or any other constructor. It's just figuring out where stuff goes and pushing it in until it clicks, but not forcing so much to break it. General rule: if you try to plug something and it's not going it, double then tripple check you have the correct socket.