For your first question, any good C IDE should provide that functionality for, at the very least, standard C. I haven't done C programming in a while, doing mostly C++ and Java development, but I would look at IDEs such as NetBeans or Eclipse with the necessary plugins to support C development. Wikipedia also lists a number of other C and C++ IDEs.
As for your second question, language has nothing to do with Rapid Application Development. RAD is a process methodology that emphasizes rapid prototyping over up-front planning and design. Although not explicitly about Rapid Application Development, Steve McConnell wrote a book about achieving shorter schedules and higher quality products - Rapid Development: Taming Wild Software Schedules. There is one section where RAD is explicitly mentioned, and it's described as "a collection of practices" that "doesn't apply to any kind of unique software".