I'd say orchestra row R, since you'll save a bit and it really doesn't feel that far away from the stage. Orchestra for this show is definitely more fun than the mezzanine IMO, and if you can get a seat on one of the center aisles that would be even better but it's not a huge deal.
Also if you happen to be going in February, there's the Broadway Week 2 for 1 pricing going on and they have some pretty good deals for orchestra.