Here was a thread where DodgeViper got a set of torsion keys on ebay for a good price. The other option is cranking your torsion bars, but supposedly some say that stiffens the ride too much. It is a free mod, so you could try it and see how you like it. If you do not like it, crank them back down and try the keys:
There are a number of companies producing aftermarket torsion bar keys. You can usually find them on eBay for a reasonable price. Buy a pair, throw in a set of Bilstein 5125 shocks, and you'll be good-to-go.