But isn't the QI the most consistent with a NI-rep?

Good point.  I would vote for the Modern Benoni after Nf3 or g3.  The resources out on that opening are good (Watson,Palliser,Vegh,etc.).  I know this opening is not to everyone's taste, but at least in this form (3.Nf3,3.g3) you eliminate the f4 and f3 lines!

I bought E.Dearing's book a few weeks ago . I enjoy picking it from time to time since it is nicely written . A special mention for the introduction !

It really depends on how you want to play the Nimzo.

If you want fairly safe and simple (not too much theory): then I would get Emms "Easy Guide to The Nimzo-Indian" and/or Aagaard DVD's "Nimzo-Indian: The Easy way" (or something like that...) 

If you want something more dynamic or aggressive I would get Dearings "Play the Nimzo-Indian" and/or the recent "Dangerous Weapons: Nimzo".  The great thing about the Nimzo is that there are lots of ways you can play it.  For instance, there are several lines where you can play ...Ne4 and ...f5 with a Dutch feel and some lines where you simply nuke the center and play the "Karpov" game.  Anyway, my point is that the Nimzo-Indian is very rich and offers lots of options for Black players, so there isn't one "correct" way to play it.  This is what makes it such a good defense, but it also makes it difficult to recommend books to you since I don't know what you're looking for. 

To be honest, I think going through all the eBooks and all the related annotated games on ChessPublishing.com will be more than enough for a good start.  There are some really great ideas out there and more than enough theory to satisify just about anyone.

Nietzsche

ps - If you're really lazy and just want enough information to play the Nimzo, I would recommend the Aagaard DVD.  Just try and ignore his bad jokes and you'll be fine. 

Depends on what you want with a book. Khalifman's Karpov book is a complete repertoire with the Nimzo of which the lines appeal to me (lots of early c5) and there is Dearing's recent book which is also a repertoire but entirely different from the Khalifman book (lots of b6). Both are good, with the latter being better in the "explanatory" department. The "starting out" book was not so good imo, especially when compared with other efforts in the series.

If it's general ideas as opposed to specific lines you're after, I recommend Mastering the Nimzo Indian with the Read and Play Method, or something like that.  I think it's by Kosten, but I'm too lazy to check.