I think you have a few options, Reddo.
The first question is how attached you are to the way the EVOs work on wave. When you try a more "classic" wave board like the Kode you will notice how easy the EVO turns, particularly in the last part of the bottom turn where you go more vertical towards the lip. So before changing to another type of board, I strongly suggest testing before buying.
But as you say, the EVOs can be a handful when it gets windy and then you can no longer access the nice turning. They can also be difficult in the top turn if you come in with a lot of speed. The way to handle this, as you have noted, is to sacrifice some volume.
So the EVO 75 option will let you still have that EVO feeling in the wave riding but be much easier and more natural in high wind and in bigger waves and faster wave riding.
The Kode 80 has a faster and more direct feel to it. You get a very nice feeling of the rail carving through the water. On this narrower shape, you can afford a bit more volume and still get very nice high wind and big wave performance. The Kode 80 will still plane very easy and early in light wind, but you need to work it more in slow waves and/or cross onshore to go vert and hit the lip as well as an EVO. The more sideshore it gets and the better the wave becomes, the easier the Kode is to ride.
So basically there are two consideration
1. Will you be comfortable on only 75 liters?
2. Do you want the turny "vertical style" EVO style or the more direct but more directional Kode style carving?
If the answer to 1 is yes and you prefer the EVO feel, then the EVO 75 is the easy answer. If you like to try the Kode feel the answer is easy too. The problem is if you are hesitant towards 75 liter but still like EVO feel.
Then one option is to try the EVO 80 xtv. It has changed quite significantly since 05 with both a bit sharper feel and significantly better high wind and fast riding speed performance. It is still about as wide, but it has a new rocker and v and thinner rails. Maybe it will work.
There is also the Evil Twin 80. Despite being as wide as the EVO 80 most people think it rides smaller, especially on the wave. This is both due to a narrower tail and due to the twin fin concept itself which makes it easier to bury the rail. The Evil Twin feels very similar to the EVO on the wave, but the top turn is looser.
So I gave you four option instead of two, so maybe I'm not helping you decide...
But I still hope the post helps clarifying what the different option might mean for you sailing and if you want to know more, just ask again.