Much depends on the type of clowns. Some species of clowns have a much higher instinct to host, than others, in my experience.
Bubble anemone is probably the easiest anemone to keep (as far as host anemones go). Clowns that will naturally take to these anemones include Tomato, Maroon, Clarkii (Clark's will take to nearly anything - very strong hosting drive), Skunks, Cinnamons, Fire Clowns.
Ocellaris and Percs have a much weaker instinct. Their natural host anemones are in the carpet family, but some will take to BTAs but it's hit and miss. Sometimes they do, sometimes they don't, and sometimes they will in time.
I guess the first thing is to decide either what kind of clowns, OR what kind of anemone you want, and then choose the other based on that.
Jenn