WRT Short Term Goal #1, Blue Tilapia would live the longest this Fall (fatal temp = 45 degrees IIRC), but IF you can still get in on Tilapia delivery this year I'd take whatever the supplier has. My Tilapia dealer (
Jones Fish) will supply either Blue or Nile, whatever they get shipped up from (somewhere) down South.
I am using 20 lbs/acre for FA control with no chemicals, but that is in a stable situation rather than starting from a bad infestation. The recommended 30lbs/acre might be a good idea at first; adjust future stocking levels based on how it goes.
I suspect that Tilapia mostly eat the FA growing on the bottom before it floats up, but I see them eating at the surface (mostly around pond shoreline) often in warm weather.
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Lots of dock options, match to your budget. I've got one cheap crappy one and one slightly less cheap decent one, both of which I built myself over pilings driven before the ponds filled up.