Imaging (in the Windows sense) Android Device?

I think I know the answer: "No Way..."

But thought I'd check because it seems so obvious now that I'm having to rebuild my tablet from scratch.

The Ideal:

• Fire up a utility and create a bit-by-bit copy of what Samsung calls the tablet's SD card. Analogous to C: or the System drive in windows.
• Squirrel that copy away somewhere - like on a NAS box
• At some later date, totally replace the tablet's "System" with that copy.

I've dabbled in Titanium Backup, although I've never tried installing a different ROM...

But what I want is different... I want to identify a "Good" system, save it, and revert to it with minimal pain/suffering/manhours/human errors when things go South.

I guess that taking the image is no problem... but restoring from it would need to be provided for by the Android boot manager or whatever it is that puts up those green character-based screens....

Is there any hope?