Dilemma: between OpenBSD and NetBSD

Hi

A client of mine asked me if I can develop a BSD project for them. I don't have much experience with BSDs, and I have been collecting some background information.
I was given the choice between OpenBSD and NetBSD.
Now, since portability is not all that important, I was oriented towards OpenBSD, which is more secure. The only problem might be the lack of certain features on OpenBSD, such as support for a modern filesystem. As I said, I don't know much about BSDs, so don't flame at me if I say something incorrect. In fact, I am asking your advice.
What I would need for my project is a filesystem that supports, at least, journaling. From what I have seen, NetBSD already has that, while OpenBSD doesn't.
Has any modern filesystem been ported to OpenBSD? I really need to know, because this issue may constitute a stumbling block to my adoption of OpenBSD.

Thanks

Ben J. Rafter