100+ gal tanks and fish (bowfin, pikerel, walleye,) small

Where are you located? You sure you can't go fishing and catch yourself some livestock?

You'll need a much larger, sophisticated system to keep all of those fish (assuming it's even legal where you are). Native NA fish are VERY messy and some require colder water to thrive (pike and walleyes). When kept at warm room temperature in a confined space, they're very prone to bacterial or parasitic infections.

In Wisconsin, where I'm from originally, you could only keep gamefish as pets if you bought them from a hatchery (I think). I'm pretty sure it was illegal to take them from a waterway (it was, at least, illegal to put them back).

Keeping trout happy will likely be a lesson in futility. Why not just buy some snorkle/scuba gear and enjoy them in the wild? Keeping them at home will be tough to pull off.

They are correct on this, you would need to purchase a Chiller for your tank if you wanted to keep these fish, especially Trout. Chillers for a tank this size would be pricey about $800 and up.