What type of clowns?
Bubble tip anemones are generally accepted by most clowns. Long tentacle and carpets are secondary and tertiary choices, but can be more aggressive with corals later.
Clarkiis will host in anything! They are not in the slightest bit picky. i would consider a member of the Euphyllia family (frogspawn, hammer, torch, etc.)
These corals will not crawl around and invariably end up in the powerheads like most anemones will and do!