Gold edition has all the extra content ever released for the game already in the disc. You don't have to download anything else. I suggest you buy Gold edition. There's no redeemable codes to miss, so don't worry 'bout getting it used.
On the other hand, the standard version of this game, simply "Resident Evil 5", requires you to buy all DLC from PStore if you want the full-game experience. However, I NEVER saw any version of the "classic" Resident Evil 5 bundled with redeemable codes.
In any case, just get Gold edition. You'll be saving HD space and $. Don't worry about redeemable codes since there isn't any and all the content is already within the disc.