I did the fuel cell thing on my early 74 260z rb26 swap. If I did another, I'd stick with the oem tank (baffled or not) and use the metal vapor tank, located on the rear pass side 1/4 panel.
I had my vapor tank out and already modified with brazed on AN fittings, which would allow me to plumb the fuel from the oem tank, to the vapor tank, then from the vapor tank to the front of the car to the motor.
You pretty much have everything you need already, to make a nice surge pot, that tucks away nicely. Just remove it, modify it with fittings, re install....