HWiNFO knows no equal
http://www.hwinfo.com/
As for coolers....
$30 .... Hyper 212
$60 .... Phanteks PH-TC14-PE
$90 .... Cryorig R1 or Noctua DH-15
$140 .... Swiftch H220-X
$150 ... Swiftech H240-X
After that we talking custom water loop
If you are wondering why there are no CLCs on the list it's because no CLC can compete with any of those coolers in the respective price ranges.
When stress testing that CPU ....
1. Use HWiNFO so you can read both temps and volumes not just for CPU but everything in your PC
2. Do NOT use Prime95 or any other synthetic program that is capable of hammering the CPU with a constant barrage of AVX instructions. If your goal is to overclock to the maximum extent you can without overtaxing with either heat or voltage under what you will use the PC for, these utilities will not answer that question.
For CPU Testing, my fav is RpG Real bench which loads AVX and CL, but in a manner representative of actual programs thereby not restricting your efforts by applying unrealistic loadings. For GPUs, I prefer Furmark.
I still use P95 to "set" my TIM by taking it up to 85C and then cool down to room temps. D+By taking the TIM thru several thermal cycles, you can accelerate the curing time and get right down to overclocking w/o worrying about what's going to change.
I look for 72 - 78C temps under the stress testing on CPU, which typically results in mid 60s in heavy gaming. With the GTX 9xx series, I haven't been able to break 63C on either the Gigabyte or MSI cards no matter what the OC