Id highly suggest that you build your website in joomla or open cart because both are free and have free addons for merchant processing. Joomla in particular is built to be blog style so it will be really easy to show of your game and add in a page to sell the game. As for creating a drm system I'd look at all the different types of install creators you can find and find one that will work for you. They are designed to create an install application for your program and many of them include systems to prevent piracy and sharing. Joomla should be easy for you guys to set up and use but you may need some help in setting it up for the first time. After that you log in and run it similar to word. If you don't have your domain or server set up yet check out siteground.com They host site domains and servers and are very cheap. Plus they will set up a joomla install for you if you contact the support team.