I don't know how Ghost has changed over the years, but when we used it in the computer shop, we ghosted a customer's HDD to another. To use Ghost as a regular means to copy your software just seems like you would be re-copying your software. It would likely be slow since you would be doing the same thing over and over again. Perhaps use Ghost ONCE and then every time you get new files you copy them to the new drive.
There is an alternative. Some Backup drives have built in software that backup your drive for you and then continue to back it up. I just use mine manually like a 500GB thumb drive. A friend of mine leaves his 1TB drive plugged in and it backs up any time files are changed. This sounds like the kind of think you would likely want to use.
I think if you are careful with a computer that seems on the verge of failure, then it will last as long as you need it to. You sort of do things like a video game, you back up the game constantly so that if something goes wrong you will always be safe. By the same respect, if you always keep your data backed up, you will always be safe with your bad news HP