You have it backwards.
You would use GV for outbound.
You also need a DID from Callcentric.
People would call you GV number and GV will forward the call to your CC number.
You need CC defined on SP2 (there is a work around).
There is a problem with GV forwarding calls to a CC DID.
I think (not sure) the problem is only with CC free DIDs.
I'm not familiar with Anveo, but if they accept outbound calls without registration you can setup E911 on a Voice Gateway freeing SP2 for CC.
CC requires you to purchase E911 with their DIDs, so you might want to switch E911 to them.
Edit:
See following for the problem with GV to CC free DID.
http://www.obitalk.com/forum/index.php?topic=8744.0