Security and data integrity of OpenBSD vs FreeBSD

[doobie0710]

I want to set up a home server, primarily for storing files and accessing them at or away from home (I will do other things with it in the future). I was going to just use Debian but wanted to give something new a try and I've heard the BSD experience is really cohesive compared with Linux distributions, which is very appealing. I hear that OpenBSD is security focused and thoroughly audited, so I am drawn to it for something that will be facing the internet and storing all my data. FreeBSD supposedly has great ZFS integration and bit rot concerns me a lot; this distinction makes choosing between the two difficult. Three possibilities occur to me:

1. set up some data integrity tools on OpenBSD to avoid bit rot,
2. harden FreeBSD (or just accept it as is, if the difference between the two is overstated),
3. use two servers, OpenBSD facing the internet and FreeBSD storing the bulk of the data and backups and providing it locally.

Perhaps there is some Linux or illumos distribution that would be more appropriate for my needs? Please advise me on which way to go with this.