FXO <-> SIP adapter

Here is the scenario…

Someone calls a phone number which leads to a facility that is remote from here (50 miles away). I want that call to be converted to IP and silently routed to our PBX here, where it is serviced exactly as it would if the phone line came in here via an FXO port.

Essentially I’m looking for something like a PAP2T box, except the phone ports are FXO rather than FXS.

I know that I can do this with a PC running Asterisk, and an FXO card, but I would rather do it with an inexpensive standalone module that converts between FXO and IP the way the PAP2T converts between FXS and IP.

Any ideas?

Sipura SPA3000? 1fxo and 1fxs port…