It comes down to your vision of how the car will be built and used.
Built two 240Z 350 SBC projects with 1989 Camaro WC T5 transmissions. First 240Z was built in 2001 for my teenage son. Car is still on the road. Second car built nine years ago. Daily driver. No problems.
Also, the T5 fits well in the car with the shifter close to the stock position.
Suggest that you spend a few weeks reviewing HybridZ threads on transmissions and purchase the JTR 240Z V8 installation manual. Many answers there.