Okay, how about a couple of dips of soulknife(2) and swashbuckler(3) then umbral disciple and finish with master thrower. While normally a soulknife really doesn't get you much of anywhere it does have a couple of features that makes it really enticing for a dip. First, is wild talent giving you the crazy various options of psionic feats. Second, is throw mind blade which has a range increment of 30. Now, psionics and incarnum for some reason or another has incredible synergy. Two feats in particular are particular nasty for this psycarnum blade and psycarnum infusion both use the psionic focus mechanic. Psycarnum blade allows an extra d6 of damage per point invested when expelling the focus and infusion maxes a selected essentia based ability so in other words free damage(psionic meditation is a must, if Eberron is allowed Heroic focus gets your focus to a swift action). The Umbral Disciple has some awesome essentia based abilities including blindsense, concealment immune to true seeing, and increased weapons reach. It also has sneak attack without needing it as a prerequisite. If you wish to cap it off the legendary master thrower gives double striking, multiweapon attacking as touch attacks for a mere price of your strength modifier. This is a bit feat intensive but if done right you can pepper down entire bosses without them even noticing you.