Voucher based programme for a joomla website

We are looking to incorporate a voucher system into our joomla website. On a similar but simpler basis to groupon. members can download vouchers for special day out, the website is for families with young children. There is no financial transaction, all we are looking for is a module/plugin that displays the days deals and allows the user to download a voucher which then can be taken to the supplier/venue. We would record the downloads and the supplier can trace the voucher code to our deal.