Well, I won't turn this into a thread to fix that problem, but have you tried these packages?
http://enterprisesamba.com/Having said that, switching to OpenBSD is not as simple. It's not just some random web server with 2 sites on it; we're talking many, many servers with a great range of software running on them and so on. Some of this software will not even run on OpenBSD at all and so on. The problems are many. :)
The big linux distros - buggy as they are - are here to stay.
Also, some interesting "statistics" from $dayjob. Our DC workload (dedicated servers) is mostly web stuff; when I joined the company in 2009 there were a reasonable amount of FreeBSD servers around; that number is now 0 (or very close); my opinion is that it went "extinct" because of poor binary updates and package management as well as lack of long term support. CPanel stopping to support it was probably the last nail in the coffin.
I'm seeing a similar thing with Debian, Ubuntu LTS took over that customer base.
OpenBSD - from our pov - is facing the same issues. I'd love to see more BSDs deployed, but this will not happen unless the above points are addressed. Add to that the lack of "kickstart"-like functionality, as well.