i know that older i5s stuggle with the game and those are 4core as well. i think you can't really just say that 4core cpus in general struggle because my fx4100 is shitting the bed, 1156 i5s do so as well and 1150 does just fine :lol:
I agree, the case suggested really is to big to be sluggin' around and will just become a pain. You could also go mini-itx if you fancy paying a bit of a premium and go for a Bit Fenix prodigy.