Uh.. all these builds are great.. but why are they in this thread? Guy is asking for a build that can divert attention without ever being seen, and strongly indicated he was mostly after a melee build, and so far all that's been mentioned along those lines is invisible lockdown crusader or invisible lockdown gish.
There's a crapton of feats, weapon abilities, and maneuvers that slow an opponent, whether by reducing move speed, tripping, locking them in stone, or something similar.
There is the Dark template from ToM, or the Collar of Umbral Metamorphosis Greater, also ToM although maybe reprinted in MiC, for huge mcbiglarge hide and move silently bonuses and EX HiPS.
There are various ways to attack from hidden, or re-hide after attacking.
I did something similar to this with a basic rogue/swordsage and smokesticks, even without much in the way of reach or optimization, I managed to keep most of the hardcore melee enemies out of the fight until the artillery got off their asses and shot them, simply with clever positioning, the trip feat, and a one-handed 10' reach weapon, without putting myself in the way of their (incredibly deadly) melee attacks. With a bit of optimization, this idea could be seriously used.