i5 and ugrade in future or pentium g3258 and gtx 960

i would go with the I5

BTW broadwell will be out on June if u can wait for two months and nvidia might make a slight price cut on the 970 and 980 if AMD does well which i hope they do coz i want a GTX985 to be released lol
 

So g3258 + gtx 960 vs i5-4600 and integrated hd4600

CSGO - would play fine on both options
Space engineers & ps2 - may struggle with the g3258 in larger maps and areas

All three are playable on intel's hd4600 graphics at 720p, although you will be on low/medium for ps2 and SE