Hi,
Clowns don't need an anemone, in fact they may never bond with one. Mine liked the intake, and output tubes of my canister filter. Get an anemone only if you really like them, they are a huge pain in the butt to keep. They find their own happy place, and it usually isn't where you want it to settle. They all sting and kill any fish stupid enough to get too close. You have to cover all intakes so it doesn't get itself sucked up and die, poisoning the tank as it goes. They need near perfect water conditions, and the strong light.
They are beautiful, and I understand why you would want one, but I had to get rid of my beautiful fish killer, and swore to never get another one.