52482 X-Cart Radio Button Group

I need someone experienced with the X-Cart software that can put a radio button group on the last page of checkout for customers to be able to select a free gift. The choice the customer makes needs to be sent to the database and then also displayed in the customers order in the administration. The selected person needs to be well versed in X-Cart or at least PHP/Smarty templates. This is for a client's web site and needs to be done in a professional, timely manner.