I have to agree, use the type of needle material you're most comfortable with. I prefer metallic in both straight at circs, but I like my dpns to be bamboo. I haven't tried the interchangeable ones, but some people swear by them. I suggest buying or borrowing something to play around with. Trial and error is going to be the best way.
alleusion on Ravelry
...I can't have too many projects, I still have empty needles...