Backup Software - Comprehensive Custom Backups

I saw a few posts on backup software, but they didn't quite cover my specific issues and needs.

First off, I have a MacBook Pro 17" That has 12 GB of EXTERNAL USB and FireWire Hard Drives - 1/2 of which are for storage and the other half I'd like to use as real time live parallel backups for the storage drives.

I'm simply looking to buy ONE reasonably priced (or free) flexible comprehensive backup software solution that allows PARALLEL REAL TIME backups of INTERNAL to EXTERNAL and EXTERNAL to EXTERNAL backups. If that cant be done then instead of LIVE REAL TIME backups to use SCHEDULED INCREMENTAL BACKUPS. I can't seem to find software that does this. I looked at SuperDuper, Backup, Backup Pro, Data Backup, iBackup, Synktron, TimeMachine, asa well as 5 different backup utilities from drive manufacturers. None of them can do EXTERNAL to EXTERNAL backups of ANY kind.

Then I was researching this a bit online and discovered Disk Mirroring, Live Folder Comparison, live cloning which left me totally confused with the terminology, methods, and various solutions. I REALLY want Time Machine to do EXTERNAL to EXTERNAL hard drive backups, but haven't found a solution.

Any help would be greatly appreciated. Thank You!