I need a solution for cooling the i7-4790k. I am worried about the temperature of the CPU core going beyond 95°C (not fahrenheit). Should I buy an aftermarket liquid cooling for my CPU for lowering the temperature or should I buy an air based cooler? The ambient temperature in the room is around 32°C - 37°C.
From personal experience, for mid/heavy tasks, the stock cooler while it does do the job at preventing the CPU from overheating and shutting down the system (in most cases) doesn't keep it that cool.
If you really want very low temps even at high loads, I would recommend an aftermarket cooler in a heartbeat.
just get a good fan (around 50 USD). and redo the thermal paste as suggested in the comment. that should work in 99% of the cases for that 1% that it doesn't work you should just replace the CPU assuming that intel's lifetime warranty will be honored where you bought it. any hydro / nitro whatever fans are meant for non-standard use like overclocking etc.