How old is your tank? Don't consider a carpet unless your tank is at least 6 months to a year old (and I'd say at least 4-5 months of decent water quality).
How big is your tank? I've got a green carpet (
Stichodactyla haddoni) that's nearing it's one year anniversary in our 75 and will soon need a larger tank (and possibly it's own tank, I haven't lost any fish yet... but these things are voracious eaters). It was a badly
bleached specimen, barely 7 inches across when I got it, but after a year of being fed properly (read: at least a tablespoon or two of ground/mashed fresh food every night) it is around 12-13" across and still growing -- and this is at the very bottom of a 75g tank with only 2x65W power compacts (although they are both 6700K so I tend to get fast growth from anything that is even mildly photosynthetic).
Damsels are WAY too big to feed to any reef anemone, they'll be spit back into the water with 90% of the flesh on their bodies not digested and send your water quality down the tubes (and thus, possibly the anemone as well). If you don't have anything else in the tank just take out the
live rock to catch the damsels, keep the rock in your water change bucket or tub the next time you do a water change so it doesn't dry out and toss it back in when you've caught the little devils -- I admit I considered feeding them to ours as well, but managed to catch them before putting in the anemone and they now live happily alone in what has become a small xenia and sarcophyton farm tank in the basement!
