I have a np300 on a 65 plate, I'm just planning the Mods to handle off road (nothing too strenuous) use, green laning and some play days. It is still my daily drive so need good handling characteristics and keep the weight down. oh and I want a lift. So not too much then.
Firstly, on the green lane front, forget it! Most of the green lanes (not that many left) are riddled with brambles that will take your paint to bare metal in minutes. Salisbury/Wiltshire excepted, but you don't need 4x4 to do those lanes.
Some AT tyres are probably all you need. A lift won't do much for off road ability, often fitted just to provide space for bigger tyres.
Recovery points and a decent tow rope are essential too.
I have Cooper Zeon LTZ 285 60 18s (31" or thereabouts) which work well.
Depending on your intended use, one mod may be....I removed the tow bar to save weight and give a bit extra clearance then cut the mount points off the tow bar (I don't tow anything) and shaped and painted them into decent tow points and mounted them using the same bolts and positions. I added a couple of decent bow shackles (3.25T) and have found those work well. The rear bumper will be the next to go....