I have no idea what is involved to do a body lift to your car so no comment re technical stuff but body lifts are illegal end of story so must be engineered, big $$$ for what you want or will get, 1 inch bigger tyre so 12 mm extra clearance under your car, nothing in the big picture.
Another issue, in Australia the laws regarding mods and engineering are only state specific so when for example next weekend we drive into SA your car is now totally illegal.
Another thing to consider, after years of 4wding I still learn every time I go out and hopefully become a better off roader every trip and have only ever met maybe half a dozen people that can get the very best ot of their car. Learn to get the best out of your car...
Lock the front and rear and you will go 99.9 % of places that someone with 35's can go, picking lines is the biggest thing when doing extreem off roading.
As far as trips requiring 33's , there are not that many and once people get to know other capabillity exceptions will / can be made , as far as I know there is only one princess on the site that gets really hung up with tyre sizing... ( a good 4wder in a car on 32's will / can do tracks easier than someone on 35's with NFI )
Another option, buy a Pootrol if you want a weekend toy for tough tracks and it will be more capable than a Navara what ever mods and $$ you throw at it.
Not saying don't do it just think long and hard about all the options...