Recommendations for #Linux storage server?

I’ve got an embedded 800mhz Via system that I’m going to retrofit with a 2TB drive for catching backups. I used to run CentOS 3.5 on there but those days are long gone. I’d rather run a rolling distro…Debian…Arch. I will likely also retrofit it with a CF adapter for the boot device. Likely I will use it for a caching DNS server, and if I have resources left over, maybe some Squid caching for the household as well. What would you recommend?