The Dewalt is not an orbital, it is a rotary. It's what the pro's use... Rotaries produce heat to break down the abrasives in a polish (to smaller and smaller particles), and do a fantastic job removing swirls and creating a perfect finish. Problem is, you can burn right threw your clearcoat if you don't know what your doing or use the wrong buffing pad....
Orbitals protect the amateurs against these mistakes, as it does not produce heat since it rotates in an orbital fashion. Problem is, they don't work nearly as well or quickly as a rotary used properly.
If memory serves, Gen II Vipers were buffed on the assembly line with 3M swirl mark remover and a rotary buffer, similar to the Dewalt. This product with a rotary and the correct pad - used properly, will remove all swirls in the paint. If you have a scratch that is deeper than the typical swirl, you may need to move up to a slightly more aggressive polish such as 3M Finesse It II, or even a more abrasive compound if the scratch is deep. 3M Finesse It II is also a great product, just a little more aggressive than the 3M swirl mark remover. ALWAYS START WILL THE LEAST AGGRESSIVE POLISH, AND PROCEED TO MORE AGGRESSIVE IF NECESSARY.
*** Don't jump in feet first with a rotary, at least on a Viper. Have a pro teach you the ropes, then practice on several lesser cars before attempting the Viper. At least that's my plan of attack.
*** You can find smaller bottles of the 3M Swirl Mark Remover a Pep Boys, or the larger 32 ounce bottles at professional body shop/detailing supply stores.