Forge and Boomba are both popular options. I don't have experience with Forge but I have a Boomba and I enjoy it. You should be aware that because of the way the car regulates pressure you'll hear the BOV at odd times while cruising, not just when shifting.
Not an issue. I leave mine on when I go to the dealer but if you were ever worried about it, it takes about 15 minutes to remove. A BOV does nothing for performance on this platform and is purely to satisfy the child within.
You can hear it here. Note that I'm in 2nd gear the entire time but it activates when I lift off the throttle, not just while shifting. You'll also hear it while cruising under steady throttle.