as long as you can't make the fins smaller or use a center inlet just stay with the fins, from the designs in your last post this one should be the best:
But performancewise i would prefere something like this but its much more complicated to mill:
I would make the waves a little longer, so that the outer edge of the inner bent of the channel is on line with the outer edge of the next bend to the other side (that the flow can't get straight through and is forced to take the bents).
The copper Rad uses a more efficient Honeycomb pattern as the aluminium rad (looks like a kind of heatercore or is it not?). I would go for it even if the alurad would be slightly better performancewise, because of the noise of only one fan. If you only plan to cool your CPU the rad will have the smallest temperature in your loop, i would wonder if both rads show more than 2° difference.