Is is possible to configure port 1 to one google voice account and port 2 to a separate google voice account?
Well, "port" has a specific meaning. If you have an OBi 202, it has two separate telephone jacks, for port 1 and port 2. It also has 4 independent service provider configurations. So, yes, you can, for example, configure SP1 to GV account #1, and SP2 to GV account #2, and then assign SP1-->phone port 1, and SP2-->phone port 2. You can do all this easily from the OBiTALK web portal page.
Just follow the instructions to set up SP1 first, including being logged into your GV#1 account in a separate tab of your web browser. After it's all set up, then log out of your GV#1 account, log into your GV#2 account, and repeat the setup procedure, using SP2. During the setup, you can assign the two different phone ports to those two different SPs.
My instructions to set up GV on the OBi: http://www.obitalk.com/forum/index.php?topic=8560.msg56460#msg56460
Even if you have only one phone (as on the 100, 110 and 200) you can still work with two accounts (any mix of GV and SIP).
Though incoming calls on either account will ring the phone you can have different ring cadences to tell them apart.
And you can select on a call by call basis the account for outgoing calls.