I couldn't say for sure but I would think that it would be the two plants with longer vegging. I am curious to see what the more experienced growers have to say. I would think more veg + more light per plant = more and bigger buds
2 plants . but why only 2 ? id go 4 vegd for 2 months , but ok to answer your Q the 2 i think would yeild more , but theres other varibals you need to consider . what system , hydro or soil ?