Buy the one that you come across first. As for the safety, personally it has no relevance for me, (and no, I don't own a Glock).
Exactly what he said. I have the 45c with no thumb safety and don't think you can go wrong with it.IMO a thumb safety doesn't belong on a defensive pistol. Especially a striker fired one. I would look for the 45c first. It's the more versatile of the two in terms of carryability.
+1 on this - if you think you might ever consider AIWB carry, you might want to think about the safety. If that isn't an option for you then from my perspective given the market, I would go with what I could find first.I bought without the safety.
Now that I am considering AIWB wish I had bought with the thumb safety.