fiber to ethernet converter...RVU.

or fiber to ethernet for JAP.

[Link: blackbox.com]

or a solution like this?
[Link: markertek.com]

Blonder Tongue would be a great source to contact if you need to convert fiber over to coax...

honestly in the end though i think JAP into a fiber to copper network adapter would be cheapest and easiest. RVU would obviously be cheapest but i have found that the sony RVU clients are slow to respond.