Most Helpful Guy
I'd recommend a desktop PC for gaming, there's more space inside it and you can put additional fans if you want to. However, for specs, I recommend at least an i5 (i7 would be better), not less than 8 GB RAM (16+ would be perfect) and for the video card maybe a GTX 970 (perhaps a GTX 750 would be a cheap option, but it won't be so great).
It'll depend on your will of playing on full HD too and stuff like that. If you don't mind for not playing on the highest settings, then you won't need a very expensive computer.