I've always noticed enhanced growth using specialized substrates over aquarium gravels and inert substrates. An example: Your building up the motor in your car. You 1st change the intake (lighting). You have better performance but you could get more ponies if you modify the exhaust (substrate). And you do that. Then you notice you can get more if you tweak the cars computer (fertilizers) . BAM another 20 HP. And on and on.
So, yes normal gravel, good light, CO2 and some fertilizers and your good to go. But in my opinion if your going all out you might as well open that sucker up and modify the 'exhaust' while you're in there modifing everything else.
Here is a snap shot of one of my tanks. The substrate is a mix of flourite gravel, sand, Eco complete, and minimal amount of black gravel. This tank is rather large and all the substrate adds up to about 200 pounds if not more. This set up is now over 6 years old so please don't mind the other specks of whatever else is in the substrate, LOL!