[Fasterthanyou]

Do your "usual accessories" include a new fuel pump? If not even a 20shot would be too much. These stock pumps are WEAK! A nice walbro 190 for like $80 should come before anything else.
I've already done a lot of research regarding N2o... I do this a lot actually... research that is, so much so that I end up finding something better to spend my time and money on... researching.... but ANYWAYS ;
There are different systems out there but most have adjustable jets, this is good. You want to adjust your jets depending on your fuel AND nitrous pressure. Pressure drop in nitrous will result in an overly rich and vice versa. Get a carb intake, a carb kit, and an adaptor plate (or must make one). Then you're set, so long as your kit comes with small enough jets for the higher, than carb, tbi fuel pressure.
An alternative is running an extra fuel pressure regulator, but that can get messy.
I think a stock TBI could easily use a 150shot at 2400+rpm and 100shot just off idle. Remember that because of the low engine speeds and tight stock cam that if you spray too early you'll have INSANE cylinder pressures. Talk to Joe (camaroracer1992) about his setup, it obviously worked but I believe he had just about every nitrous goodie on the market.