I assume also that you are talking about slicks for drag racing. If so, you know that there are no ET streets for the stock Viper rims? Also, there are no "standard" after market 16" rims that fit around the rotors, etc., so you're talking about custom wheels. So, now you're talking $1200+ for custom rims and ET streets for the rear. Next, once you do that, you need skinnies for the front, unless you really want to die from total loss of handling. Plus, they will help bring your mph back up. So, now you're talking another $1200+ for custom skinnies. See John Purner for all the above.
Now that you're out $2500 or so, you might as well drop another $800 for beefed up half shafts. First, you're kidding yourself if you think you're only going to make a couple of passes, especially after dropping some fairly serious money to get the slicks in the first place. Second, and more importantly, you don't want a half shaft failing on you. It pretty much ruins your day or week, and it may cause a lot of collateral damage. I speak from personal experience.
As far as launching technique, after you do a good wet burnout, rev to about 4000 rpm (depending on your track conditions) and dump the clutch. It is so much easier to launch on slicks than on stock street tires. I agree with the above comments -- get Tom Welch's drag racing video. You will learn a lot.
I was a little surprised to hear Tom say that ET streets don't matter much for a stock Viper. Since I didn't put slicks on until after the mods in my signature, I cannot say what they would've done when I was stock, but they knocked a good 0.5 sec off my ET. (Also, for G-Tech 0-60 runs I went down from 4.1 sec to 3.6 sec.) I guess if you're really great at launching on street tires (which I bet Tom is), and you are on a sticky track, you're probably already seeing 1.8 sec short times stock. ET streets for a stock Viper might drop you to 1.7 sec short times, 1.6 sec if you're lucky, so maybe Tom is right, assuming you are really good at launching on street tires.
By the way, were you talking about drag racing???