The only quest mod that comes to mind on "Go here and kill this and get a reward" would be the New Vegas Bounties Mods. In the mod you play as a bounty hunter but at the same time these mods have a story to them aswell, there are tons of bounties to do in these mods.
New Vegas Bounties I: http://www.nexusmods.com/newvegas/mods/37310/?
New Vegas Bounties II: http://www.nexusmods.com/newvegas/mods/41184/?
Sorry man, these are the only ones i know of, hope i helped