So I finally got my sump put together and it was too easy! It goes as follows:
C-siphon overflow (800gph) that runs into a filter sock in said 20L tank.
Next a bubble magus BM180A skimmer.
Then a "refugium" environment containing liverock, macroalgae and bristleworms that hitchhiked on the algae...in a pond basket. Dome lamp with plant light clamped over it.
Next are two eshopps foam pads used as baffles.
Finally a sedra 700gph return pump....
So there it is, the lazy non-handy persons sump...and so far so good!
Any thoughts/changes/additions? Was going to put carbon in the filter sock...
Thanks for everyones help and input!!