Telecom Convertors for DS1/DS3 signals

All:

I am looking for recommendations for devices that can take a
DS3 signal 
from a carrier via coax, convert it to optical so I can use
fiber across 
buildings to transport the signal, and then on the other
side, demux the 
DS3 signal to individual DS1 channels and terminate them on
a RJ-48 
port. Any suggestions? I am only looking at one DS3's worth
of data to 
transport across buildings. Distance is around 1000 feet.

Thanks!

Devon