Hi I have had a look into download managers over at the Firefox Add-ons site and have found quite a [https://addons.mozilla.org/en-US/firefox/extensions/download-management/ few extensions] that might help. Firefox already includes some [https://support.mozilla.org/en-US/kb/where-find-and-manage-downloaded-files-firefox download management options] and these extensions (either on their own or with others) will extend this. I hope this helps, but if you have any further queries please ask and we will do our best to help.