Automate addition of Opportunity Product Revenue Rows

When my users create a new opportunity we need to have three specific products added to the opportunity (Opportunity Product Revenue).  I could make them add those manually, but want to automate the process at create time.  This needs to happen in near real-time because after they create the opportunity and the products are added they may want to adjust the standard price.  What is the best way to do this?  I know workflows won't work.  Java script?  Is this a good application for REST APIs?  Traditional Web Services?  Thanks in advance.  -  Mark