I actually have a Hogue EX-01 4" Tanto Blade Aluminum OD Green, despite it being above what I generally consider my price range, but I came across one for a price I couldn't pass up. It is definitely an awesome knife, very light for it's size, awesome button lock and not clunky at all, but with a handle about a half inch wide, I wouldn't personally consider it to be 'slimmish', although getting into that size range of knives, you probably can't get very much slimmer.
I also have a Zero Tolerance 0350, 0550 and 0700 (tanto) (wait a minute, didn't he just say the Hogue was out of his price range?) and while they can be compared to each other, I think it is difficult to compare them to the Hogue, since the Hogue to me is so different from the Zero Tolerances. Before making this level of investment, I think it would be worth handling a Hogue and a ZT if at all possible, so you can get a feel for the differences and see what you prefer.
Actually, I had forgotten you said you specifically wanted a tanto, which rules out the ZT 0350 and 0550. Between the ZT 0700 and the Hogue EX-01, discounting the 0700 can probably had for less money (I actually paid about the same for both, but as I mentioned, I got lucky with the Hogue) and despite the fact that I am a huge Kershaw (and therefore ZT) fan, I would definitely PERSONALLY consider the Hogue superior to the ZT 0700 by a long shot.