What I have is their Forwarded Local Service (http://www.voipo.com/local-voip-number.shtml) which is $4.95/month and I use the Obi110 ATA (http://www.amazon.com/gp/browse.html...=A4VT9X8JBKS16) which is $49.99 one time charge.

I have configured the SIP account on VOIPo and set-up SIP account on Obi110 SP2 for incoming only and its been working flawlesslessly. I use Google Voice for outbound and inbound calls on SP1 using Obi110.