SFI 3.2A/1 should be all you need. Some tracks have funky additional rules, so I'd find out before you buy. IIRC at my local tracks, if you run a non OEM power adder, you need the jacket. If you run 13.99 or quicker, you need a helmet. Snell rating of some sort, M rated helmets may be allowed but check with the track. They may have a FAQ on their website on vehicle tech and personal safety.
Also, be sure your nitrous bottle has a current DOT stamp on it. If it's new you should be fine. I had to have min re-certified to run. Bottle brackets were allowed to be plastic at one time, they need to be steel. Lastly, check rules on bottle blow down tubes. In a hatchback Fox they need to be vented outside the vehicle, but if you have a real trunk, you may not need to. I would do it anyway, for safety.