Is the 2009 Area 51-R1? In what country are you going to use it?
Area-51 R2 dp/n 800GY Delta Electronics 1500w / 1440w 12v Max Power Cord
original power cord
My cord is 10feet long, 60c temp insulating jacket 300v 14awg, plug says 15amp 125v. My beefier 6foot cord for Nzxt Hale90 1200w is rated 105c 300v 14gauge 16amp 125v. You're encouraged to google-fu the above specs. A C19 sqware 14awg 6-10ft with a wall-socket male-pronged-end appropriate for your country 'should' suffice
Low-power & non-server-grade PSU's will most likely use a C13 (5 15p) 18awg|16awg (fatter)
Area-51 R1 1000|1100|1200w >< R2 / R3 / R4 850w >< Aurora R1-R6 460|525|850|875w