If data safety is ur main motto, go for 1TB mirrored drives.
Costly but money should not come b/w u and ur data
If u want, other cheap solutions would be, 1TB drives from WD or Seagate.
U can get good deals in eBay.in (if u don't trust eBay, try to venture in ur local shops). Price would vary from 4500/- to 5000/- for these drives.
Always checkout for warranty 3yrs and 5yrs warranty drives would cost u diff.
Always remember ur hdd can crash anyday :evil laugh: