Well, I've gone and done it now...
As you can see this is not exactly the "small" tank I was talking about. Santa was very nice to me so I decided to nab a pre-drilled 90g with stand, skimmer (bubble Magnus curve 5), and return pump (fluval). Bought a 30g long to use as a sump, grabbed some man made rock for $2/lb. Have salt, test kits, refractometer, heaters, power head.... I think I'm ready to get going on the plumbing!
This is my plan for a sump. First section is for the drain (Herbie), not planning on running filter socks full time but may throw a sponge or something at the bottom to collect detritus. Skimmer, etc section next followed by a fuge. Bubble trap baffles into the return pump section.
Main question-
How big should the return pump section be? Planning on one sqft for skimmer, one sqft for fuge, and the other sqft between the drain and return.