Take into consideration when looking at backup software
How you approach your system backup depends on a couple of factors.
Take a look at your installed programs, preferences, etc. and think of the time it will take to re-install each element. If you would like to save all your settings, etc. and avoid re-installations and losing mail data, etc., it is a good idea to have at least a semi-recent drive image of your root or C drive. A general backup of your files and folders will not save your OS settings (registry included). With the drive image, you can easily replicate your system on the new hardware.
How reliable are you at scheduling a backup of your files and following through with it? If you are erratic at best, look into the following archiving software options that will preserve your necessary data.
If you have a few extra dollars left over from your birthday check Aunt Bertha sent to you, consider a removable or exterior hard drive for storing the large drive image you will create. It is a safe way to keep your OS settings and important data since it is not operating all the time. Then when you add new software or upgrade, simply make another drive image over the old one.