OBSD is UNIX, .. SELinux is Linux. If you want a secure, efficient,
compact OS done by folks you can trust and actually talk to, use OBSD; if
you want 'fairly secure Linux' [which has had thousands of hand in it
including NSA, as mentioned previousy], use OpenSUSE with ***AppArmor***.
Simple and easy to implement, even by less senior Admins.
SELinux is **NOT** ready for primetime, unless it's changed tremenduously
in the past couple of years. Last time we tried it, management was totally
arcane and the machines would lock up on a regular (monthly) basis. It
wasn't worth the time to troubleshoot so we went with AppArmor for that
application.