Reading back through this post, I had pause to consider your goals for food fish and some of the comments.

Crappie in a pond this size could produce some nice size fish, yet when the Crappie have that inevitable "boom" spawn, the entire fishery will be stunted rather quickly...It would take an Army to remove a couple hundred thousand (or far more) 3 inch starving crappie when it happens in a half to 3/4 acre pond...Preventing Crappie from overpopulating and stunting a pond takes very diligent and labor intensive management. Angling alone by only a couple individuals will not prevent it.

I noticed you discounted Hybrid Crappie...I offered that suggestion as an economical alternative if you wanted the angling enjoyment and as a way to avoid the inevitable overpopulating and stunting that will happen with standard Crappie. Whether it is a waste of money to add some fish to catch as needed every couple years versus the costs of draining, re-stocking and waiting for fish to mature every few years is the more economical is a question only you can answer. The angling pleasure is always priceless, but when does it become work?

I never mentioned tilapia at all, but they definitely do not eat "only" phytoplankton...in fact, they eat extremely little phytoplankton and in a crappie pond, Tilapia may well be the only fish that could produce enough forage by utilizing food sources no other fish can in the pond to delay the pond's eventual stunting after a boom crappie spawn. Tilapia are used as a tool to support other fish in most waters in the most economical and natural way, NOT as a sustainable pond fish...they just also happen to taste great.

If you want this pond solely as a food fish producer, making it easily drain-able/seine-able would be the best option, but adding the fun factor of fishing is what you want...Right? We just through ideas and options out there for you to consider.

Red Flags popped up and sirens blasted in my mind when I read you suspect and have evidence of underground streams!..These can make building a pond very problematic if not impossible to build. I would STRONGLY suggest you try to get an NRCS agent out there to do some bore sample to see if a pond would even be economically feasible in the site you want it built. Streams UNDER a drainage system means it is a "losing" stream and overcoming that will be expensive at best.

More food for thought...in your location in western Ky, you can purchase catfish in the 8-12" size for under $.30 each plus your fuel/time to pick them up in central Arkansas.

There are no set rules on how you wish to reach your goals, it's always a learning experience, but having the wrong info or conditions sure won't make reaching those goals easier. We all want a pond that is just how we like it...getting the fish, weather, soil, terrain, and infinite variables to cooperate is a real bugger though.