If you just want it as a dummy ie converter for your fiber to ethernet then anything would do really since this is not processed intensively.
We have a
Gigabit Internet by Blazenet in the office and are using
Syrotech SY-
GPON-1000R-DONT as Dummy PON. It's working great with no issues and is small and uses very less power, so we have it connected, chucked it in a corner, and forgotten about it.