I've read it's not a good idea to mix northern LMB with Florida strain or Hybrids. Is that true?
I'm leaning toward stocking 50 Northern LMB.
I think that depends on your goals?
Lots of experts on Pond Boss concerning LMB stocking (not me). However, I think "experimental" data is also very valuable.
Are you able to affordably stock small batches of LMB? (For example, pick up yourself, or you are close to your fish supplier so the delivery fee is relatively low.)
If so, then you could try all three types and mark them. See which thrives in your pond (for your goals) and favor the winner for future stockings (or cull the others selectively moving forward).
P.S. What is your approximate latitude in E. Texas? The experts may need that to give you their best advice. The farther south you are, the more advantage to the Florida Bass in getting bigger.