Been considering this myself. Most poo-poo the idea for the 8, but having ridden in the back, I think it would benefit some passengers (preventing airsickness) during turbulent conditions.
Haven't seen an RV8 specific yaw servo mount but one may modify one designed for the RV10/14 using a pitch or roll servo. The design would require deconflicting with pitch servo system...
Obviously would require the "with Yaw Damper" option for the control head (which would be the way to go if considering a future install)
Good luck.