There's no WAD at all. Do NOT use NUSDownloader.
Be sure to download and extract the FULL archive, with keeping the folder's layout.
You need :
apps/homebrew name you want here/boot.dol
apps/homebrew name you want here/icon.png
apps/homebrew name you want here/meta.xml
apps/homebrew name you want here/ciosmaps.xml
apps/homebrew name you want here/v7/
apps/homebrew name you want here/v8/
apps/homebrew name you want here/v10/
Then in the installer, you can press Dpad Right to scroll from v6 (internally included in the installer) to v7, v8 and v10 (externally included in subfolders if you correctly extracted my installer package)