Welcome to the Nissan Patrol forum. To post a question and to see less adds on the forum then you will have to register
first. We are an easy going friendly forum so join in the conversations and feel free to ask any questions.
Become a forum sponsor for only $20 and see no adds with faster page loading times and many extras benefits.
I would echo what some others have already said and from my own experience I would suggest a good chip, a 3" exhaust, an EGT monitor and a Dawes valve is all you will need to get a reliable, better performing vehicle that you can enjoy for years. There are heaps of extra mods that can be done but - how deep is your (or my) wallet? This is plenty and relatively inexpensive (for the results anyway).
Chip-It are an excellent product - possibly the least expensive of all the chips and a good company to deal with. You get the USB with all the tune-ups on it so you can bung it on the lappy and adjust as you wish and for whatever application - mine has 17 different tunes from factory to full comp - I run it on a 4 for around home and put it to a 7 or 8 when hooking up the camper and heading off - lift it up to an 11 if towing and hit strong headwinds or mountains - only takes about 3 minutes to set up the lappy and do the adjustments. Much improved performance and better economy at the same time - cant get better than that!
Plus I can leave it on and working when I get services done and that is at Nissan so no dramas there either.
They are about $1100 to $1300 which is far better than almost all others.
Manta make a great 3" exhaust system for the 3.0 - mine is turbo-back as I got rid of the cat, so quicker response and low-down torque is a heap better - probably about $1150 fitted.
The EGT gauge and Dawes valve you can fit at home and they will be a big help in keeping an eye in all things that make us nervous - if you want to get someone else to do the work then the EGT can range from $250 to $500 supplied and fitted, the Dawes Valve should cost under $200 supplied and fitted.
Hope this helps (and no, I am not affiliated with any of the products, they just work and I am happy with them).
Good luck Thomas, and have fun in the Patrol no matter what.