You don't need a 9 or 10 speed chain. You need either a 9 speed chain or a 10 speed chain. They are different.

If you need a 9 speed chain get a SRAM PC 951, PC 971 or PC 991.

If you need a 10 speed chain get any SRAM chain that model that starts with PC 10--.

Figure out how much money you want to spend and then buy the model that is at that level.

It's so easy.