Here's what I've been able to gather from rec.climbing.
From Ed Diffendal:
when you get down to Huaraz go over to the Thai restaurant and
ask for Narasuan. I know this sounds random but he can give
you the best first hand beta for great bouldering plus rock
climbing on Esfinge.
From Sparks:
his email is: naresuan@hotmail.com
cool dude, great cook, penchant for jack daniels
From Jason Perez:
You can also find out info at Zarela's:
"La Casa de Zarela"
Lodging and Mountain Adventures..!!
Julio Arguedas # 1263- La Soledad
Huaraz-Peru
Phone:(51)-(44)-72-1694
www.zarelaz.cjb.net
e-mails: zarelaz@hotmail.com
zarelaz@latinmail.com