I don't know of anyone on this board that drives/races Vipers for a living. We all do it for fun - as a hobby. Especially for that reason, safety should be the primary concern. When Skip Thomas talks to drivers in the challenge series, he often points out that many of them are posting faster lap times than some of the drivers in the race group, but most likely don't have any of the safety equipment required to race in the VRL. Buying a dedicated track car with a good cage, fire suppression system, and maybe even a fuel cell, will at least give you more confidence to improve your driving ability by knowing that you have taken the necessary steps to be safe. A good race seat and a 5 or 6 point harness help anchor you in a position where you can get more useful feedback from the car as well as reduce your own fatigue.
This doesn't mean that you have to jump right into the race group. I drove for a full season in the Michelin Challenge Series before deciding I was ready for the wheel to wheel experience. Learning to gradually improve and lower your lap times is essential to becoming a better driver and the Challenge Series time trials are a proven method to acquire the necessary skills. As a beginner, consistent dedication to your own improvement along with getting the seat time in a car that won't hold you back can yield some remarkable results. As long as you follow a plan such as "a - b - c - d etc.," and don't try to skip steps by ignoring the process, you will be amazed at the progress you can make.
I attended 2 three day Panoz racing schools and participated in their racing series during the time that I was learning to drive the Viper. I was impressed with the school and appreciated the fact that the cars they used were purpose built race cars and had all of the safety equipment that I believed made sense. They hold schools at Sebring, Mosport, Road Atlanta and Texas Motor Speedway. All great tracks. The Panoz doesn't have the horsepower or torque that the Viper posesses, and because of that fact, it is a little easier to learn the importance of momentum to being fast. If you scrub off speed through a turn and then get on the gas in a Viper, it can still seem to be fast, but in aything less, you immediately realize the price you paid in the sluggish response to regaining that speed that you lost. It is every bit as important in driving the Viper fast, but just harder to recognize. Don't get into the useless excersise of comparing the two cars. They are different, but they can both teach you many things that will help you become a better driver.
There are many reasons why a properly prepared track vehicle is safer and superior to a street car. You don't need to be intimidated by it, just strap it on, be comfortable and learn from it. Good Luck!
PS. I drank the purple koolaid in the fall of 1999 when at 46 years old, and took a ride on a whim in a Skip Barber street viper at Limerock. As a passenger, I was completely amazed. I bought a 2000 ACR and started looking for track time. I attended the Panoz schools and met some of the regulars from Viperdays where I found out John Cooper's Viper was for sale. I purchased it and attended my first Viperdays at Mid-Ohio in April of 2001 and have been hooked ever since. I'm 50 years old now, in better shape, and feel much younger than I did before I caught this disease.