Preservation Server

My institution is going to be purchasing a preservation server sometime
within the next year. I'd like to solicit advice on specs. I know this is
highly dependent on our collection, but I'm looking for some baseline
hardware recommendations. We'll be using it to store preservation-copies of
electronic files that belong to archival collections. Most of our
electronic files are not born-digital, but we are preparing for an influx
of born-digital records.

Any advice is appreciated! Apologies for cross-posting.

Thanks,
Nathan Tallman
American Jewish Archives