2017 5k imac upgrade

Thanks to all who have posted on this topic. I've read a lot of build/repair reports, and just wanted to make sure I had the latest info/recommended parts (and my facts straight). Given the complexity of this process you can understand why I'd like to do it only once. In addition, it's...

Hello. I purchased a used delidded i7-7700k and will upgrade my i5 2017 5k iMac. I want to relid the cpu and was wondering which Thermal paste is best to use besides liquid metal? (Previous owner used LM). Also this is my first time relidding a cpu. I have the delid/relid tool and will reseal...