dell support
You can't find your drivers on the dell support web site? I've never had a problem finding anything. If they sold the computer, the drivers (and crapware) are there.
Of course you could face the situation where they have the win8 drivers but no win7 versions, i.e. no support of the "downgrade." But that would be counter to their normal practices. All the (many) machines I've "downgraded" to win7 pro have had the drivers available at dell support.
So are you facing the situation that they provide win8 but not win7 drivers? That would be a new, and unfortunate, development.