I've run air deflectors using several different mounting methods, and yes, I run the deflectors in addition to using the Cone cooling kit. The methods I have tried are;
1. Brackets from Woodhouse. These are V-shaped pieces of aluminum flat stock which bolt to the factory holes in the Deflectors, then are secured to the Viper's control arm using hose clamps.
2. Brackets from IPS. Widely referred to as "Dilusi" brackets, these bolt to the factory holes in the Deflectors, then bolt to the Viper's control arm. This is what is shown in the Illustrated Upgrades (although the Deflector's are mounted upside-down in the photo)
3. Several schemes using just zip ties.
I was never very happy with the brackets because bolts through the factory Deflector holes force the Deflectors to ride in front of the Viper control arm, thus rubbing the rims at full lock. The brackets also tend to have the Deflectors riding low enough that they rub the ground.
I wouldn't worry too much about which mounting method you try first, even a small "off" results in the Deflectors being damaged, so you'll get several chances to try something new!