I'm afraid you will run in trouble with many "exterminationists", for the camp of "deniers" includes everyone, who does not accept the basic tenets (the exterminationists have the exclusive right to define "denier"):
1. six million,
People who agree with all three points I laid out, but claim that the number of Jews killed was significantly lower than the lower bounds set by historians, could be called "Holocaust minimizers", but not deniers. I would disagree with anyone calling them "deniers".
2. large scale usage of gas chambers,
There are people who agree with the three points I laid out, but don't think that gas chambers played a significant role, and are thus called deniers? Can you point out where? I'd like to see it.
And I wouldn't consider people who claimed this deniers.
3. organized by the state.
There are people who say that, in German controlled territory during WWII, millions of civilians were killed, but that it was
other civilians who did it, the Nazi government wasn't involved, and the Nazi government wasn't involved in any sort of systematic killing of civilians? I've never run across such claims. Could you point them out to me? Depending upon exactly what their claims are, I might have to refine my definition of Holocaust denial.
I find it strange, that you seem not to know the reason 9/11-investigator asked
Please give me a list of all the Nazis who testified at the NMT that the 6 million holocaust happened
1) Given that, so far as I can tell, 9/11-investigator doubts that Nazis systematically killed civilian Jews
at all, asking for a Nazi who testified as to the number of civilian Jews they killed seems like a red-herring.
2) Thus far, I haven't seen 9/11-investigator claim anything like "Even if the Nazis systematically killed Jews, it's only the Holocaust if they killed 6 million, so if they killed less than 6 million the Nazis at Nuremberg who admitted to killing Jews were admitting to committing something
other than the Holocaust". If he
has said something like that, I consider arguing over what name to give the act of Nazis systematically killing civilians to be nothing more than a word game.
3) The exact number of people killed in the Holocaust is a matter for historians, not the Nuremberg trials.