Ask Slashdot: Migrating a Router From Linux To *BSD?

An anonymous reader writes I'm in the camp that doesn't trust systemd. You can discuss the technical merits of all init solutions all you want, but if I wanted to run Windows NT I'd run Windows NT, not Linux. So I've decided to migrate my homebrew router/firewall/samba server to one of the BSDs. Question one is: which BSD? Question two: where's some good documentation regarding setting up a home router/firewall on your favorite BSD?
It's fine if the documentation is highly technical, I've written linux kernel drivers before :) (Got a question? You can Ask Slashdot, too.)