If you are looking for a 2 TB storage drive:
Western Digital WD AV-GP WD20EURS 2TB 64MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive - Newegg.com
When you get the new system built, you can, if you want, put this drive in an external housing and use it for keeping separate backups.
Rosewill RX-358 U3C SLV Silver External Enclosure - Newegg.com