I use an inverted rubbermaid with slots in it to fit over PVC pipes.
I think a fake rock would look a lot better. I can cast one I am sure. I assume it will need lots of ventilation. The sun will be beating down on it.
My last Sequence pump lasted 6 years. It's protection, I felt was mediocre at best.
How much ventilation should I have. I suspect a few holes is not enough.