I'm much more familiar with OpenBSD and FreeBSD on the server-side, and I don't feel real comfortable with Linux. The two biggest vendors, Red Hat and Ubuntu, don't really give the warm fuzzies. Maybe something like System 76 backs.
What about plain Debian :) if you’re comfortable with BSD then Debian should be a cakewalk for you.
The funny thing is I tried to setup and Arch Linux box. I can setup OpenBSD with thinking with all the partitions and such, but that Arch Linux install was just a bad time. I'll try Debian when I get back to work. We are replacing our Samba server and the BSDs aren't real current given some changes the Samba team made.