I run a startup course and want my students to set up a landing page but without the monthly recurring cost. Is there a one-time fee Wordpress theme?

The theme should be able to accomplish the following: 1. Visitors to the landing page sign up or complete a couple of questions 2. Upon signing up, the page generates a special URL for them to share with their friends (to create virality). 3. Use the URL to track your most active referrers and reward them for spreading the word. The closest I have come to is http://launcheffectapp.com/ but their designs look terrible for our purposes. If I could replace theirs with a beautiful landing page that might work. Could anybody help?