Old Problem - Better Idea?

[Saltcreep]

Hello all,

I'm about to build/rebuild a sump for my 55g (FOWLR, for now), salt tank. I have been using a 36", 26g tank as a sump, but it's really more for additional volume and easier top-ups and WCs than anything else. I've been procrastinating for a long time because, having built a 15g sump from an old tank for my 60g cube, I know what a PITA it can be. However, I've come up with a build method (probably not original) that will let me build a more complicated setup with little grief. So, I'm looking for ideas on the best of the best designs. What should be in it, in what order? I've read about having a refugium, DSB, reactor section, skimmer section, a place for live rock and for competitive algae, bubble traps, return section, filter rack, - it goes on and on. Bearing in mind, that I hope to transform this rather boring tank into a reef system, what's really necessary here? I've looked long and hard on-line for designs, but all that's done is confuse me even more. The DT is a standard 48" 55g tank with an internal corner overflow 1.5" bottom drain. Return is via 1" PVC split into two dumps into the tank. Return pump is a MAG 9.5. The return feeds sit about 1 cm below water level when the system is running. The overflow is set to maintain the water level just above the trim on the tank. I hate waterlines. This setup allows the sump to run with the level only abut 2" down from the top. I know it is relatively disaster proof because twice a day, the pump automatically shuts down for ten minutes while the auto-feeder does its thing and the siphon at the return dumps breaks before the sump overflows. The only possible way I can see of making a mess would be if a leak developed in the overflow tube or bulkhead seal.
So, as I said, I can make this as complex/complicated as I want, within reason - if you were building a sump, how would you design it? What components would you include or exclude? If you could point me to any designs you've found that you thought were particularly good, that would be fantastic.
Oh yeah, I plan to build this whole thing on my workbench. Sort of like making a sump with no bottom or end panels. It will be built shorter than the 36" tank length to accommodate the two end sections and then I'll just remove the top trim from the tank and slide the whole shebang into the tank and seal with silicone. It won't even matter if there are minor leaks in the sump itself because everything will be contained within the outer tank. And, no worries about breaking the sump trying to squeeze baffles in there and seal them.

Thanks for reading, and looking forward to some inspirational ideas.