I'd choose Bill Walker way over Darius Miles... In a heartbeat.
What does Darius Miles have to do with Bill Walker?
They'd be competing for the same spot. and we're running out of roster space.
Darius is more of a PF at the moment. In fact, I'm not sure if he can play SF at the moment which is why I don't see the correlation between him and Walker.
So as far as I see it, if we don't keep Baby you can go after Miles and a backup center. Cut Pruitt, get another PG and the a Wing. So, I don't think that an addition of Miles would affect Walker.
Not saying that this would be my plan, but if some sort of plan includes Miles, it would be something similar to this.