A nice small tank, maybe like a nuvo all in one would be a great choice.
They come from 4g up to 38g. Make it an invert tank with bigger hermits and shrimp. That would be awesome. I;d say around 3 he will actually be able to enjoy the tank. My girlfriends baby is almost a year old but loves to be held up to the tanks with the fishies. lol He puts his hand on the glass and tries to touch them, it's adorable.
I still have a 125g freshwater tank and yep, alot less heartache and worry. I'm not entirely sure how many fish I have now in it, but they must be happy as they all grew from about one inch up to about 8 inches.
Glad youre still around Lefty, I missed all of you guys.