IIRC, the Blind-sight feat is from Sword & Fist. The PC probably meets the pre-reqs already. One was Blind-fight (which he has). Another was WIS (something...), but being a shaman he probably meets that pre-peq too (although S&F had a few feats intended for higher level monks with a WIS 19 pre-req!). I can't remember if there was also a BAB pre-req... If there was, it was a mere BAB=1, so he'll definitely qualify for the feat by level 3.
Like the majority of posters, I'd be very careful about giving out any bonus for being blind. Consider the presedens you'd be setting; you probably don't want every future PC in your group having some disability the players are expecting to be "rewarded" for. He would naturally have immunity to gaze-attacks, and a minor competense bonus to Listen (+1 or +2) also seems appropriate.