I have an 06 Wrangler Unlimited with 4.0L.  I was wondering if there is a kit out there to put a NOS system on my jeep?  Also, does anyone have any advice for running NOS?  

i dont think unless you are drag racing that nos would be practical. nitrous ruins engine internals. this is a quote from gale banks,   "nitrous oxide is a drag race tool, it is rarely used anywhere else, so if your life is 7 seconds fine. my answer to a nitrous guy is: get a better job, earn some money, supercharger charge the damn thing, turbo charge it and then if you want more, then put the nitrous, because the thing about a supercharger or a turbo charge is: when you push down the pedal, its there, theres no tank to go dry." that is a direct quote. i would not do a nos kit. i would go with a supercharger or a v8 swap, if your looking for stump pulling power maybe a diesel swap would be the thing you are looking for. it will cost you more but in the end you will be satisfied.  

took the words right otta my mouth.....

do you have a lift and big tires?....  

I have 6" of lift with 33" Super Swamper SSR, AEM intake, custom bumpers, winch, etc. My Jeep is automatic and I was just wanting the extra umph for when I run in our local mud bog.  4High doesn't want to spin those tires.  I know I need gears, but I was waiting to lock both diffs at the time I replace the gears.  Any ideas to get those Swampers really going for a few seconds in the mud?  

i would wait and hold everything until you get the gears and then go from there. after the gears you wont want that nos im betting  

I'm wanting to go to 35" tires what gears should I run and still be able to drive my jeep everyday if I want?  I have a company vehicle for work, but sometimes I still like to drive my jeep.  

the person to ask is mud. your gonna have to let it known what tranny you have. your pinion and for sure if you are gonna be running 35s  

my choice is a 5:38 for the 35's with the auto,

If you're doing high speed fwy driving for long periods of time daily the 5.13 or 4.88 at the very highest will give you back the stock spunk it used to have.for normal driving conditions the 5.38's are gonna be about the best overall for a commuter that hardly goes over 60mph, stop and go, and trail riding.

5:38's @65mph it'll turn 2300rpm.
5:13's is 2200
4:88's is 2100

taking a guess you have 3.73's now and with the 33" tires it turning about 1700 @65 so the ID is nearly useless besides downhill and on the flats.  

Yeah, I have 3.73 right now.  I have the d44 rear and d30 up front with an auto tranny.  I was thinking 4.56 gears were extreme, but your suggestions seem way more extreme.  I do more sand, mud and trails than rocks so will I still be able to get the wheel speed with those ratios you mentioned?  

yep.. way more speed and torque than you'll get using the higher ratios, cause it won't be grunting or up against the stall to get them to turn..the deal is you will no longer need to use the low range in the sand or mud in most situations.
I'm going to a 5.38 this summer cause the 4.88 isn't low enough. I spend alot of time in the soft sand on the oregon coast and sticky mud near home.