OK.. if you want the "best" ie: last boat available go to Seawolf's download page and look for Gunsub Beta which will start your campaign with a VIIC41.
Also, if you want to MANUALLY edit the .upc files dont forget that your not looking in the UPCData file rather like Ducimus noted you go to UPCDataGE.
Finally if that doesnt work do it the old fashion way