As an MS3, when sould I start looking into and setting up my away electives. I've heard to do it early. Plus, do most people go to places where they want to match or do you go to reach programs to work with someone well-known and get the LOR.
I would start researching aways in Feb/March. I think it would mean more to MOST programs that you rotated there and shined than having a LOR from a big shot. A great letter from that program's faculty would also be huge. I say rotate where you want to match.