I’m terribly sorry to inform you that it seems that we will be getting an even more complete extra extended edition for the 25th anniversary, at least that’s what Peter Jackson seems to be indicating in the commentary of the old extended edition.
The book is a good read, though The Two Towers drags a bit. I do wonder for people that saw the movies first, if you’ll be as offended as a certain subsection of the fandom that just cannot understand why they didn’t do a line by line recreation of the book. (Spoiler, it wouldn’t have translated to film very well.)