Ben is another one of those characters where I’m not sure there is suitable material.
Using only the maskless dialog from Lego TFA doesn’t give good results. Adam has an audio book but it doesn’t sound like him at all for some reason. I tried his TED talk but there’s too much background noise on his AI voice. Honestly, I think the only option would be to trim his TLJ lines out of that movie and use some software to remove all background noise.