For starters, Welcome to the wonderful world of Sub-Zero OC @Walkerj12
What are your goals? Do you want to run benchsmarks?
Maybe it would be cool to do 3 stages of PC hardware.
For example, you pick a few benchmarks, like GeekBench 3 and CineBench R15
And run them at stock, documenting the voltages/MHz temperatures and scores.
Do a "normal" overclock, with ambient cooling, air or water. Document again,
And Freeze it! Again the same! That way you can can calculate the scaling of core clock and benchmark score with voltages/and temperatures.
First, and maybe not so relevant question, do you have a CPU container?
Now platform wise; currently the only "real" viable XOC retail board for 8700k is the Maximus X Apex.
Also, for serious overclocking, especially with LN2 it is required to delid the CPU. There are a few special rules applying to delidding and mounting an IHS(intergrated heatspreader) and CPU for LN2 overclocking. But I will leave that open for now. Sadly liquid metal does not work under extreme conditions. We use conventional pastes. With a twist, specific for subzero.
Good pastes for LN2 are; Thermal Grizzly Kryonaut / KINPIN Cooling KPx > Gelid cooling Extreme.
Gelid is the cheapest. Isn't as good as the other 2 but should work fine in your case.
Nothing else is viable, period. Don't try, it has been done for before you. It will save you lots of hours and headaches. And prevent you from wasting lots of liters LN2
Generally, the LN2 base profile that's stored on there is a OK starting point. It also comes with an RSVD switch, which is a physical dip switch that automatically sets certain voltages on post to help eliminate the CB and CBB (Cold-bug and cold boot bug, coldbug = system lockup at a certain temperature, for example -120, coldbootbug is when your system temp is too low to boot, in that case you need to warm up to X temperature, this varies per platform and even CPU!)
Most XOC guys set a certain baseline OC in bios, with rather conservative vcore, let's say 5.5Ghz and 1.5v. (This while you are already at -100 to -120)
Then boot, pull down to full pot,(-190~)run a benchmark at this 5.5/1.5v baseline, with realtemp open to check for a paste crack. If you don't see positive temps, you're good to go.
(Remember, you can always clock higher with LN2 on the same voltages compared to air, due to how semiconductors work, "shrinking" due to cold, lessening the leakage, = higher frequency at the same voltage.)
I'd suggest, before you go all in on the platform. Learn it's quirks on ambient cooling. Prepare, setup your bench OS, and test it before you use LN2.
If you have any questions, feel free to ask them!
You can also head over to our Hwbot team section, there's lots of info about LN2 OC too!