A new pc for Civ... And more..

[GianlucaG]

I'm ready for a new Pc.. actually I'm a macbook air user.
I'm searching for maximum resolution and best graphics.. can u suggest me the best configuration to play Civ at the best resolution..
I'll hope to pay maximum 1.500/800$..

can u suggest a good configuration please?

And I need a small case in is possibile..
thx