My advice would be to get a USB 2.0 docking station. You can plug in relatively cheap external drives to use for backup. My first USB external was a Seagate 500 GB. I think I got it on sale for around $120(this was a couple of years ago.) The docking station will cost you about $30 to $40 and you can buy internal Sata drives to plug into it for around $60 to $100 ea. depending on capacity. I'm using a couple of WD Caviar Black 750 GB internals.
It may seem like a bit of cash initially, but it's so much nicer to just start the backup and go watch TV for 20 minutes(well I run my system drive lean and keep stuff on my Seagate to keep the backups small and the defrags fast.) With the size you are talking it might take 45 minutes. But it's hands free. Go make a coffee and a sandwich.
Plus I found my WD HDTV player set top box supports USB 2.0 docking stations. I get double duty from these drives. I have a partition for backup images, and another for video. I can swap them between PC and player without unplugging any cables. It works out very well.
If you want faster throughput USB 3.0 stuff is coming out now. But you'd have to put in a card if you have a slot free. Just for doing backups though, USB 2.0 is plenty fast enough. Way better than burning discs.
The main thing with any image backup.. boot the restore/rescue CD and see if it recognizes your HD in the restore program. If it doesn't, save yourself some heartache and get another that does. I use Macrium myself and like it quite a bit.
If you don't want to go with the docking stations then I'd recommend watching for USB externals to go on sale. With USB 3.0 coming out I imagine they should start discounting the USB 2.0 externals soon.
