Well i would go with Test server where i would take a month to go through OS and setting up running as my requirements..
at least.
As i already pointed out i don't want to migrate at all what is currently working very well with FreeBSD.Then i will make migration plan and make test migrate from FreeBSD to OpenBSD ...then will make clean Server instal and do migrate my data. Hope this helps .;)
This is all about future needs.

