Yeah as said, Clarkii clownfish are very aggressive and grow to be big bulldog like fish who'll mercilessly defend their anemone.
So you'd need a widish tank of at least 4 foot to have an aggressive clown species (most of them) with another.
If you do get the percula ( or probably more likely ocellaris) clownfish, they're unlikely to host unless bought with an anemone, and even if they are, the Clarkii will bully them straight out of it. The H.Malu anemones they're known to host are about thee most difficult anemone to keep too, so I'd really avoid it until you're well into it, at least a year away.
What size tank is it going to be?