Nitrous can be a very viable option for na engines where mods arent possible, or labor/time/money make them problematic. Following some basics helps. A modest 50-75 HP (You can change nozzle orifices in minutes)wet shot wont wear your engine quickly, and give it an honest difference you will feel on the "ole butt dyno". I would recommend a TPS activated one.
Some things to consider. They run about $600 for a decent kit. Average cost to fill the bottle-$50. (10-12 good runs) You want a minumum 9-12 inch tube in front of the TB so the nitrous/gas mix vaporizes adequately. You can minimize the danger of preigniting the spray by not spraying before 2000-2500RPM, and having a "window" where you can let off the accelerator gradually after spraying as to not allow the mixture to collect in the intake. You also want copper spark plugs in good shape. Learn how your car will react to it in a safe setting, try it in going through 2nd gear to start. My GXP has tried to turn me sideways spraying in 1st gear and recovery with torque steering a major pain.
As with any mod that delivers this much more horsepower, regardless of the type of mod, you are adding stress to the entire drivetrain and wear is certain. There is No such thing as a safe power mod. Increasing cylinder pressures is going to increase wear linearly regardless of how you go about it.