If you want to stay with a VII and you intend on trying to survive the whole war, then you should at least take the VIIC. The thing is that the VIIB has limited upgradability while the VIIC goes all the way to the end.
I don't usually like going from the VIIB to the VIIC, but in the long run its better. Me, I don't usually last long. Either from DID or SH3 Commander retirement.
