Re: replacing the springs - I think it really depends on what and how you intend to use the LC.
If you're planning some overland trips with all the extra weight that might mean you might want stiffer/stronger springs and shocks. If it's just a daily driver and family car you may want to keep it near standard for comfort etc.
Horses for courses really....
From a personal perspective, I "upgraded" to 50mm+ Ironman springs and shocks setup over 10 years ago, plus LT rated AT tyres - from a completely OEM setup on Dunlop AT20s.
It has certainly ruined the ride comfort, which was limousine-like before and increased road noise and harshness at speed. However the handling (obviously a LC is no sports car, so I use the term loosely) is much better and it doesn't wallow so much during cornering. The trucks stance is also hugely improved with the suspension lift and (slightly) oversize tyres, which are on 80 series rims in my case. So ultimately it's been a compromise I've been happy with so far.