IMHO, the very best sump you can buy is a empty tank (petco 1$/gallon sale) with a few baffles added. You can then make it to suit your specific situation - for my 120gDT, I used a 40 breeder divided into 3 sections - first is where the drain lines go and where the skimmer sits. The second is a small refugium area, and the 3rd is where the return pump sits and the dosing pumps lines are located. Total cost for the sump, including the 1/4" glass baffles was under $100