Given dancer's high natural evasion rate, even at 90 all I use for evasion gear 99% of the time is 2x evasion kila +2. I have capped evasion, full evasion merits, and full Closed Position merits, but I don't wear evasion gear. Most of the time I use RR/VV/GH atmas.
Now, I also carry a full evasion set to macro into when massive links happen, or when I'm tanking something especially nasty, or need to hold the mobs attention without hitting it because we can't find a proc. I also have Siren Shadow and Cloak & Dagger atmas for those times when I need them (read: hard solo or tanking something hard). I would recommend you carry a full evasion set and get those atmas as well, but you won't use them often.
As for the daggers, I want to say that most of the time on dancer you are soloing or tanking. If you really want to help your dancer, I would suggest 2x evasion kilas +2 and capping and meriting evasion. I am also a huge fan of 5/5 Closed Position. Once I got the daggers, evasion merits, and Closed Position merits and I hit a level far beyond anything I could do before on dancer.
And, off topic, but I personally prefer Cloak & Dagger to Siren Shadow when tanking because it helps land steps. Too often I wind up in full evasion gear, back tanking and spamming Animated Flourish while people redo dirty procs. In all other cases I prefer Siren Shadow to Cloak & Dagger. Once again, 99% of the time I'm using Voracious Violet instead of either of those.
Best of luck. Dancer is a lot of fun!
Edited, Aug 14th 2011 10:21am by Thydonon
Thydonon - PUP99, SAM99, WAR99, DNC99, BST99, SMN99, BLM99
Pandemonium rest in peace.