How easy are your frag tanks to maintain?

So how easy is frag tank to maintain? I am thinking a 40 breeder. The reason I am looking into a frag tank is to frag and sell some of my corals as they get bigger and to move some of my smaller fish from my DT into. I am looking into a fish that has the potential to eat my smaller fish and I don't really want that. A frag tank would let me move the fish, and make just a little bit of money every now and then. The problem is that I don't really want to maintain another tank to much, but if they are not difficult then I might just do it. I would plan on adding my 2 Percula Clowns, my Yahsa Goby, and my Sixline Wrasse to the frag tank. Would it be good to have a skimmer for this tank since I would add 4 of my fish to it? If so what kind? One of my clowns host an anemone as well, and I don't know if it's good to separate the two of them, so I might have to add her host to the tank as well. Unless she will just find something else to host? Also, how would I plumb it to my DT if there is two skimmers? Can I do that, or should I have it be separate? I am trying to make eveything as easy as possible so I can do what I want with my DT and to have a few coral frags to sell. Thanks!