You need to find any template for this purpose or hire a Blogger expert to design a template for you. Default templates at Blogger will not let you create any coupon site. They are simple templates for blogs.
@dhamu89, how dynamic does the site need to be? Simple static coupons shouldn't be a problem on blogger, a more dynamic setup (link tracking, affiliate link cloaking, etc.) would require a shared hosting account and domain name.
Yes a template for blogspot is need it in order to have a coupon script ( with click to copy coupon ).
You can make one simple with direct links that have you aff id.
However your major problem will be updating and deleting the coupons. There is nothing automatic for blogger.