Very applicable:
http://reefcentral.com/forums/showthread.php?t=2447396
Folks enjoy complicating things. The fancy production sumps look cool, but that is about where it ends...
There really should not be any debate on the socks, but it is what it is...
What type of drain system are you planning with 4 drains? What size tank....
Your return section(s) is way too small, and that is actually more important than much of the rest you want to put in the sump. ATOs fail everyday, you don't hear much about it, as folks have a tendancy to not make threads concerning their failures...
UV has a purpose for fish only, but for a reef type setup is is worthless. However, running a uv on a quarantine tank has some value...
I see you are planning GFO, does your system need it? It certainly is not needed in a new tank...in fact it is questionable whether the skimmer is needed for a period of time (months) after the initial startup...allowing for it is fine (GFO) but you should hold off on the implementation till you know how your system is going to run, you may find it is useless (as many other have) and can be detrimental to your system as well, depending on conditions....