As others have said #1 will do the job, but their expectations should be tempered. Even people with extraordinary computers struggle with performance issues with that game specifically. The engine that game was designed on was not made for the type of game they made and it has been struggling since day 1.

I love the game, put many many hours into it, but even with a brand new rebuild that is closer to option #2 but a better processor, slightly worse graphics card, and more memory, my computer struggles a bit with it and I get noticeable performance drops.