A variety of ICC–based software RIPs are available from numerous manufacturers. However, there are many varieties of RIPs, each offering a differing interface for color management and production features to choose from. In addition to specific features, other selection factors when choosing a RIP are its ease of installation, printers supported, screening technologies and learning curve.
Almost all RIPs need operators with specialized skills, or at the least training to operate. See if the manufacturer offers training classes for the particular RIP you are thinking about purchasing. Download a demo version of the RIP to "test drive" it. Look for potential pitfalls, output issues, ease of operation, screening technology (output) and color profiling modules.
Talk to others about what they are running. Make sure you get a RIP that can grow with you as you change or add equipment and add additional digital equipment to a given workflow. RIPs sometimes come in different "editions", with various aspects of productivity missing in order to lower the price. Be sure that the RIP you want to buy has the features you need now and the capability to grow with your business.