To me it would depend on how your aquascape is going to be. I know you are doing the bonsai island type theme with the scape but if you are going to have rock work closer to the back I would go with the position on the left if your rock will be closer to center of tank I would go with orientation on the right. I would imagine there will be so low light spots since you are just running three lights so in my opinion it would just depend on where you want the shade to be.