I would expect that with just one output at 3300 GPH, you're going to have some places where the flow is way to high and some where it's too low, but I haven't used a WavySea, so I can't say for sure.
I would always advise more than one source of current in the tank. It's important to get water flowing everywhere from different sources to create random turbulence.
It's the random turbulence that's most important. I like to have at least 2 sources of alternating current so you get lots of random combinations. i.e. 2 WavySeas on different settings, or 1 WavySea and an alternating power head wavemaker, etc...
But everyone has their own personal preferences. Your best bet is to try some different setups and see what you like. PVC is cheap! (unfortunately pumps are not, but hey who can ever have too many extra pumps around!)