[Chicago] Looking for leased server colocation (OT)

[Phil Robare]

A friend with a three person business wants to set up a server for
backups, document sharing, email server, app serving etc. I think a
leased box at a colocation service is a better choice than turning her
closet into a machine room but I have never been involved in
purchasing such.  Can any of my fellow Chipsters recommend a company
they have been happy with or give me any hints as to what to look for
/ avoid?

Thanks,

Phil