When I go to Amazon and searching for DDR3 1600...there are so many choices.
Is there much of a difference if it works?
You might be surprised at the lack of difference.
Their not that many places that actually make memory.
It's more like company 1-10 needs X amount of DR3 1600 with 9 cas. They start producing the memory usually with not specific parts just what is available.
They produce X amount needed by company 1 using their heatsinks and stickers and when that number is filed the production line keeps running but switching over to company 2's heatsinks and stickers, then move to company 3's order.
EDIT what to avoid is the no name Chinese memory.
Back on DDR2 memory it was pretty much buy you a 1GB or 2GB stick and put it in and it would work with what you had.
DDR3 was about the same until you got into trying to mix low and high density memory.
DDR4 got a bit worse trying to add more memory and I would think DDR5 will be worse than that.
Reminds me of a friend of mine back in the day when you could buy a 30 buck or 80 buck car battery. He said they would start production of batteries that required the size to be X by X by X with say 325 cold cranking amps. They would stop the line to change stickers so you might pay for a Sears Die Hard for 80 bucks and it was the same exact 40 buck Wal-Mart battery.
I recommend GSkill memory they have excellent support and very good returns if it fails.
They are some companies that actually have their own plants.