I suggest tracking your pond temperatures this winter. You aren't planning to buy shad now, anyway, and you can collect valuable data for the next year, starting now. Measure temperatures at different depths, top to bottom, in two foot increments. Write them down, log individual readings into an excel spreadsheet, and look for patterns at all depths. It won't take many months to make your decisions easier.

Teach a man to grow fish...
He can teach to catch fish...