Im looking for a Fiber (not copper) SFP at 2.5 gps that supports turris omnia. Im worried about Electromagnetic interference so I rather have fiber.
Have you seen this doc and links?
The generic compatible modules from fs.com do a great job, so maybe try them and report back your results in the wiki (Supported SFP modules [Turris wiki]).
So in theory should this fs module work? Generic Compatible 2.5GBASE-SX SFP Optical Transceiver Module (MMF, 850nm, 300m, LC, DOM)