I need help with some parts for my pc build

[Dropment]

i was planning on building a pc in the next coming weeks and i talked to some people about cpus and i went crazy. At first i was going to wait until ryzen 3700x came out to build my pc then my friend was telling me that ryzen wouldn't last that long compared to intel. Now im here now looking at 9700k, 8700k, and a hint of ryzen hah. I have my case and psu already (h400i and corsair cmx650). I saw the cooler master 212 got a revamp so im going with the black edition.
for the 2 intel cpus, is a higher price chip with better thermals better than a lower price chip with okay thermals.

 

[hang-the-9]

Not sure what "not last that long" means exactly, the Ryzen CPUs are a good pick, there are a lot of new builds using those CPUs, they are a good alternative to Intel. Tomshardware has buying guide link off the home page, take a look there.