In my opinion your rod is a bit too short for popping , get an 8' rod and with TP10000 + PE5 line , you should be ready to tackle a 25 kg GT .
For popping around the reef , one should get at least a cast of 60+ m in order to reach the target , if you happen to chase schools of tuna , a longer cast may be necessary in order not to spook the tuna .
Jon .