If you really want to do it right, then this is my idea. Get one of those all-in-one utility sinks that they have a Lowes or Home Depot. They are around $88. It has a 21 gallon capacity, is on legs and has everything you need to install at home to water supply lines or hose.
Then you can hook up just about any pump or filter assembly like in livewells or fish tanks. It is all fiberglass or plastic so easy to drill holes in to put in any plumbing fitting you need. That utility sink will be easy to modify to any need you have. And will be fairly easy maintenance. You will then have just about what any baitshop has for their minnow. Keep in mind that if you hook it up to city water, etc. that the chemicals such as chlorine, etc. may kill your minnows, so you might have to add a treatment.