The Bladesinger chain is (SPOILER) -
on the Black Dragon that you have to get one of the sacred items (the cup I think) from. You can't miss it
Also, a Bladesinger is a fighter/mage (I think), not a bard, though a Blade is much more like a fighter/mage than a regular bard.
There's lots more Elven Chain in Suldanesslar, very handy if you have a lot of multiclassed mages.
The only non-Drow elven chain you can get outside Suldanesslar is a non-enchanted suit of ordinary Elven Chain on one of the feuding nobles in Trademeet, and some Dark Elven Chain on the Yochlol that eventually appears and tries to kill Viconia (if she's in your party)