I'm a little spoiled with my sacked out wake. From what I see I think that your wake would be a difficult wake to surf on any thing but a big board.
The wake in the first picture looks small but OK, the second looks washed out.
Looks like the river's pretty long and wide. Try turning just a little. If your surfing on the port side turn slightly left. That will clean up a washy wake shown in the second picture. If you turn too hard the wake looses its push.
You could spend $400 or more on a bigger board or about the same on some fat sacks. In the long run smaller boards are more fun to ride. Get a boat load of people on board and see if you like the wake with more ballast. Can you get out to some place that's deeper just to see if there's a difference.
Here’s a picture of the wake on my Lightning with 2,000 pounds of ballast. The Avalanche is supposed to be a better surf hull so with a little work you should be able to do better than my wake.