Conc uses ias from all gear.
Other good gear to consider would be a sa fort, ecara, prudence, eth upped hades.
My favorite conc armor would be a glitched gbane though.
They are very hard to get. they provide huge defense, cbf and a socket that can be used for ias

Type of armor can greatly effect your ias though.
You may need 20 ias/str gloves to hit max breakpoints with some of the armors.
Cannot be frozen is a must. And usually means sacraficing a socket or ring to get. glitched gbane being a very good exception.
Very high defens, 2os visionary helms can also help keep that high ias while using armors like fort etc...
using rends is also good but makes it very dificult to hit the max ias bp.
That said...max ias isn't always needed, but if you can get it without compromising your gear it is vcery helpful.
You usually have to sacrafice an ias breakpoint for using damage gear like rends and sa fort.
Its a tradeoff really.
A well built concer can usually have a setup for max ias/defense and one for less ias/damage without gimping youe build and wasting stats.
A lot of good options really.
This post was edited by Ashikaga on Jan 22 2010 01:43pm