Back in the game! Could use suggestions..

[Scythanith]

A 40g breeder as a sump as Bblinks suggests will hold most practical equipment such as the skimmer, heater, some filter floss and maybe a reactor if needed.

Easiest way is to do regular small water changes. From there you get into dosing and that is best with a doser unless you're super reliable to manual dose.

Lights, get a single used G4 or something like that.

Plan out the area under the tank and think about where things will go before you put water in it.