It will work, but corner overflows will result in splashing noises as water surges into the overflow and some loss of wave height.
If you are choosing one or the other, the 6105's will be the way to go, they are essentially the foundation of a good flow set up, the wavebox only creates a wave, which lacks any direction and it is a great addition to a good directional current, but in most cases is not suitable as a sole source of flow. The wavebox will produce a bigger wave with less power than a pair of 6105's, but the directional flow of 6105's is more important to the health of the tank than a wave.