I would personally stay away from large 'nems in your tank. They COULD move a lot on you, and you would/could sacrifice your mixed tank just for the 'nem.
Then, there's times where it will move twice in a given year. Too unpredictable, IMO.
If you had a less established tank, maybe, but with the SPS, I wouldn't want to sacrifice those just so my clowns have a host.
They will host in an assortment of corals. I've seen a pair of true percs host in a large colony of paly's.