How do the choices of programming style and development process influence one another?
They don't need to have any bearing on one another, but hopefully they're the kinds of things you think about together as you begin a project.
Iterative processes are easier to implement with programming methodologies that support componentization—the object-oriented paradigm. Linear processes are suitable for all types of programming styles, but are not necessarily the best match.
The developers' prior experiences and their personal preferences for programming style will have the greatest affect on these choices.
Which is the best programming style?
Trick question! If you actually gave an answer, put down this book and ...