Sillyfishies
Aquarium Advice Addict
There's not much cold water species I know about. They never interested me. You could do the 2 goldfish in a 50ish gallon tank with decent filtration and easy maintenance.
There's several interesting subtropical-friendly fish species out there. Longear sunfish, orangespotted sunfish, dollar sunfish, and pumpkinseeds are some of my favorite colorful native sunfish. There are also several shiner species that are amazing.
The containers that you linked, one is basically a half barrel, which is a 50ish gallon barrel cut in half, which is good at being decorative but limits your options to very small fish.
A stock tank might be a better option, there are multiple sizes available.
Tuff Stuff Products Heavy Duty Oval Tank, 110 gal. - Tractor Supply Co.