I'd take the Tapajos II personally, as they'll probably be more accommodating to future plans with the tank given their location.
With that said however, the only issues with the balzanii is the cooling period which many regard unnecessary, and G. megasema being from reasonably far south and that I have absolutely no experience with anything regarding them.
With that said however, the only issues with the balzanii is the cooling period which many regard unnecessary, and G. megasema being from reasonably far south and that I have absolutely no experience with anything regarding them.

