I'll help:I never expanded past a 10g, which I no longer have running. I couldn't come up with a concrete, useful plan.
Make a rectangular pond of desired size.
Make a grow bed with gravel as substrate, all excess water should flow back to the pond.
You can grow onions,garlic, chives and others easily in the grow bed.
Water doesn't necessarily have to flow thru the grow bed continuously, a few minutes every day is sufficient for most plants.
Since you wish to grow kosher species as food, I would try to go with: bluegill, a few crappie, some LARGE golden shiners and lake chubs (to provide additional forage),
And tilapia.
The standard blue tilapia survives temps as low as (sometimes lower than) 55 f.
As a food source you could use a mix of purina pellets,grasshoppers and crickets,cooked rice and bread .
(The bread gives the fish a better flavor).
Given enough room bluegill won't do much fighting.