There is no definite answers to such question as both engines are quite different and is just a matter of what your needs are and what you really enjoy in an engine.
The 4A-GZE in general, like most forced induction engines, provide very deep torque range from low to mid rpm, and provides the driver a similar feeling as larger displacement engines. The power output is provided low in the rpm range. By contrast the 20V and modified 16V engines, being naturally aspirated, requires much higher revs to get similar output and torque curve is steep and narrow at the top. The more aggressively you tune them the more this is apparent.
The 20V with it's VVT operating, provides more stable higher torque output than the 16V but is vastly lower than that of the 4A-GZE. Novice drivers will definitely be faster with the 4A-GZE while more experienced drivers will find very rewarding challenge from the 20V while showered with the concert of individual throttles all singing like the best of racing motors. All this however is provided that you had installed and tuned the engine well, which seems to be more of a problem for beginners. In any case, never budget your project short, or cut corners on parts needed, or else your project will just be that...a compromise, even when just installing it using OEM specs.