Hmmm, there's a lotta unique figures I could go for f rom Yavin.
Lots of the generic mid-level officers would be good army building figures. The Rebel Honor Guard is a good idea too with their pikes and dress uniforms.
A generic Rebel Pilot that saw headswaps would be good too... unique heads for red and gold leader, and then a generic young pilot. Each with a unique helmet (The generic guy with the standard blue emblems/black visor deco).
Personally, I could go for a new rebel fleet trooper as the "Ultra" figure in the set. Give him a collapsable look-out tower, scanning pistol, articulation out the whazoo, removeable helmet, and blaster with a working holster like the last one shoulda had and that'd be a dandy figure by me.
With Dodonna and Antilles (Odd that Antilles is included in a wave for Yavin when he wasn't near Yavin in the movie) confirmed I'm not one for more of the officers in that uniform like Willard and crew...
A technician with removeable helmet would be a great asset though too! They could even reuse the Imperial Officer's body with new legs and new arms. Include a helmet and a headset you can remove and he'd be even better for army building.
Astromechs are ok, but I'd sooner see character figures over simple astromech repaints... Though there are a good many of them floating around there it seems.