Finally made it! G.Skill 4800LA working!
My overclocking nightmare is just gone away. The set of memories, that I bought some time ago - G.Skill 4800LA, which I presumed to be failing, is installed and working.
My DFI NF4 for about half a year was unwilling to cooperate with those mems, which was driving me somewhat crazy - the sticks were bought from the second hand, the previous owner assured me about theit correct operation. Still I was not able to stabilize them.
Then I got a diabolous idea - mix them with 2×256 regular Twinmos sticks (I think they have Powerchips onboard). Mixing G.Skills with Patriot LLK kit was unlucky, so I thought “what the heck”. Imagine the smile on my face… 
So now I have 1,5 GB of RAM, probably even a bit faster than Patriots before (233 6-3-3-2,5 2T as opposed to 215 6-3-3-2,5 1T) and it made me think - maybe 2 gigs are possible. I have even spotted a 512 A-Data TCCD stick which will make a pair with mine, so it’s now only waiting for payday
I will post some screens later, maybe some benches as well.