Timing Source - UT50 no longer supported?

Hi All,

I recently migrated my organization away from TrixBoxCE to FreePBX BETA-3.211.63-6.
It looks that the sangoma that we were using previously is no longer supported and I was wondering if someone could recommend a viable replacement.

Our plan is to eventually migrate to a virtualized environment, I know this isnt strictly supported but with ESXi allowing for what appears to be genuine pass through with very little knock on effect I would like to experiment.
If anyone has any experience with this I would also love to hear it.