First, what exactly are you fighting? This determines the stats your going to need.
I do VWNM's as RDM/NIN with Almace + STR Shamshir +3. Working on a DA+10% sword but it's become a side project to be getting my Hyksos Robe.
Even with CDC being a 60% DEX WS you still need attack and lots of it. The STR Shamshir +3 has +25 attack (5 from STR), that is incredibly hard to beat. The only thing that competes with it is the DA+10% sword. Unfortunately it has too high of a delay for me to be comfortable with. Both weapons have the same DPS after factoring in DA / Temper. So it boils down to what is better for your build, +2.5 fSTR and +25 attack vs +10DA.
I wouldn't go for the +DEX one, accuracy is ridiculously easy to cap / fix now, it's attack that we have a weakness in.
-=Edit=-
Crimson, T.Knife is a horrible off hand weapon. Its only value is a nice screen shot worthy WS once per 50 WS's. Not only must the QA proc, but the additional three attacks must land. You end up with an Asuran Fists situation. At capped acc only 69% chance of all seven hits landing.