If you can, it would be a good idea to use a 20 gallon for the sump, I have a 10 Gal. for my sump and it gets so small once you start adding equipment. For a skimmer, I would suggest the Reef Octopus 5 in. internal space saving protein skimmer, for the ATO, the Tunze Osmolator universal 3155 auto top off, for the heater, 100W Eheim JAGER Aquarium Heater. There are also many reactors out there you might want to look in to. It also might be a good idea to upgrade the return pump to reduce the number of power heads you'll need in the main tank. I love all anemones systems, I used to have one, can't wait to see how yours turns out.