It isn't necessarily a TE that is needed. In addition to Walker and Davis, the 49ers also have Byham coming back from injury. Harbaugh also liked Reuland enough to keep him on the PS all year long to gain strength/size and experience.
What the 49ers need is a TALL, AGILE receiver with speed enough to demand attention from a safety in addition to a corner. I know that is not an easy find but Harbaugh clearly understands that need or he would not have taken a chance on Braylon Edwards. The fact Edwards did not work out has not changed the need for a guy with his general size/skill set. As someone else already said, the scouts should be looking at college power forwards who will not be good enough to go to the NBA.