Nutech, G.I, PCQB and CAC, they sell affordable parts. .
I'm not sure sa NH-D15 kay murag dako2 man sya basin masangit if you have high profile RAMS (katong mga dagko og heatsink). If you can extend your budget pwede kaayo ka mo kuha any aftermarket cooler, but then again that is just "optional", the intel stock cooler will do the job nicely (since you are not overclocking)
Kna syang NH-D15 d kaayo na importante if we'll apply it on your part (you're just using it for gaming not for overclocking), better prioritize some other parts or your GPU and spend the extra bucks on important parts on your RIG, pwede pd ka magpuno og SSD if you want, but mag agad ra jd na sa budget nimo..
If you think about it kanang mga PC's sa Internet Cafe, some are playing for games, etc. .mo last man lage og how many years, just using the stock fan. .again, intel stock cooler will give you a reasonable temps, not in the case nga to the intend nga maguba imong CPU tungod sa temps.. under full load 100% kana cguro imong i3-4160 using stock cooler around 70-80c, and those are just normal temps. .you'll start to worry if temps reach around 100c+ up already. .