I think maybe the 3 350s... The big 650 is a monster and your kinda stuck with a big tent for just that.. If you go for 3 350s at least you can swap and change tents in the future and have some flexibility.. I think the 350s will be easier to dial in...
I run 2 x 300s in a 1.2 x 1.2 area and barely turn em past 2 notches at 24 inches to dial them in to each stage of the grow..
They are stunningly good lights but were not really designed for tents in mind... Rather big rooms with lots of lights up high n bright for room coverage... So in little tents like ours they kick arse at low volume.. So I think a 650 is a bit over kill.