Hi, sorry to hear about your husband
.. I guess you are right, a fish tank would probably help him.. change his mind and all..
Well.. I would take a 20 gallon tank, small but still big enough for a few fishes. Instead of using a filter I would use a protein skimmer only, no filter. Prizm skimmers are about 70-75$ (flying FIsh express have the cheapest I found). About same price as a filter but personnally I prefer filterless then skimmerless.. You could use southdown sand and a bit of live one to seed it. Cost less then using totally live one. A few pounds of live rocks, for bacteria and also for looks .. As for hardy and colorfull you could have a pair of clownfishes (true of false percula are the ones that stay smaller).. they usually do not hide and are active little fishes.
Since they do not eat plants you can add some colors with macro-algae. The one I like the best is called Halimeda.. looks like a cactus, and do not grow as fast as caulerpa.
Ochlodes (blue balls) are nice too. And red tang heaven also.. 3 different colors. All 3 do not grow too fast.. Since there would not be any corals, cheap NO hood that are sold everywhere would do just fine, even with plants. You would still have to put a power head I guess.. but you do not need a powerfull one since no corals, and not a lot of live rock to cut on the circulation. A few snails, like nassarius to stirr the sand, and astrea snails (cheapest ones but also the best in my opinion).
HTH or at least give you a small idea for making your own..good luck..
