nitrous guys, how did you retard your timing?

[bottlefed8]

I come from a long line of domestic projects. On those platforms I always just bought a handheld programmer. I see that on my '98 SC400 I need a piggy back or stand alone. What's my best option to use for someone to do a solid nitrous/street tune on my car? Also, can anyone suggest a lexus/toyota experienced tuner in the eastern half of the us?

Thanks!