Most of the sweepstakes doesn't allow emails and even YouTube traffic. If your current network has offers which allow this, then you are lucky go and hire a writer to write the swipes.Talking about those walmart survey, kohl survey etc
I saw in adworkmedia, there are usually 1-2 banners, you can always find it on google imagesAlot of CPA networks have sweeps, but i havent found one that provides graphics/html/etc for their sweeps that we can use for email