You might well consider to upgrade the DD design to lvl. 5. The upgrade from DD-IV to DD-V is worth better than from DD-V to DD-VI.
Are you expecting fights in Home islands? Or what is your reason to build infra in there? (except a secret Japanese Manhatan Project like )
Are you expecting fights in Home islands? Or what is your reason to build infra in there? (except a secret Japanese Manhatan Project like )