I don't think that the waves are necessary, but hey, it might improve things a little. It's more likely to create some deadspots though (indicated by the bubbles on your pic), or some less turbulent spots anyways.
I'd stick with the straight fins. I don't see the purpose of the holes, if the flow rate is high.
To build it, I'm thinking baseplate, CNC some shallow grooves, and braze the fins in place. Dunno about the top yet.
So this design of yours is for a pelt? I ask because the channel is so large, and that brings up the issue of using a manifold to get the water in and out, so that the flow is spread evenly. I'm not there yet...
