I would:
1. Check to make sure that they will allow a convertible w/o a rollbar. Some events don't;
2. If you are cleared, I would bring your car in to your Viper tech to do a good tech inspection (hoses, belts, fluid levels, wheel bearings etc.). If you are emechanically inclined, you can do this yourself);
3. On my 2006 Viper, I used 30 psi rear and 34 psi front to dial out a little understeer.
4. Otherwise, the stock 2003-2006 Viper is a pretty fun/formidable track car right out of the box.
I would seriously consider getting a rollbar like the Autoform if you will be doing track days. When mine was installed on my 06 my Viper tech showed me the stock Viper roll hoops and they are basically thin, hollow aluminum tubes with a rubber coating around them. They are not really designed to withstand a rollover and the Dodge attorneys have done full disclosure by saying as much on the warning label on the door sill. Please protect yourself.
/Rich