I use NG. Of course there were several generations of NG. I came to it during the time of the Ron Jaworski "7 Minutes To Better Golf" DVD, and that is more or less what I use. Later they suggested moving the lead hand grip down to the fingers. Eventually my NGCI had me do that.
I tried IMA and felt it was pretty close. But his drills were counter-productive for me. I also tried Graves. Just IMO, he probably has done a great job of breaking down what Moe did, but that doesn't mean it works for others. Some of it is probably just Moe-specific. I couldn't get anywhere with it, and it actually set me back.
That's the thing, we somehow have to find a way to swing that is natural and effective for us as individuals. IMA is good. Graves is good. But they didn't fit me. The NG drills, as much as they were mocked at the time, work very well for me. I found my old CI, took two lessons, and this year am getting back to hitting it better with my arms taking the lead, as Ken Martin also advocates.
I have never owned NG clubs. Any regular clubs will work, as long as you get fitted for lie angle and flex, just like any other golfer. I build up the lower portion of my grip to take out a lot of the taper. I've messed around with grips WAY too much, it's been a wild goose chase.