I had Gabriel Safari's on my 4.5 1998 Patrol. They are not designed for the weight of a Patrol. I had to replace them after 5000km. Not worth trying them.
Koni is probably the best shocks you have on your list. I think they are also serviceable.
I am not too sure about the Monroe's. The Old Man Emu (OME) shock are made in the Monroe factory. Should be not too bad.
When lifting your car by 50 mm they actually replace the springs with longer ones. The shock is just longer to accommodate the longer travel that the car have. The shock does not lift the car.
I bought 4.8 springs on the forum from Izak. I then bought Billstein shock from the supplier in Bloem and let one of the off-road workshops put them in for me. The springs lifted my car probably about 50mm (unfortunately I did not measure the before and after). The current lift is passably the original height of the car. The springs I bought the car with was shot. The current setup made a huge difference!! Drives like a totally different car. Replacing the petrol pump also made a difference. Goes like a sports car now.


Koni is a more expensive than Billstein's when I did my research for shocks. I got very good service from them. Unfortunately going cheap on Patrol shock is penny wise and pond foolish according to me. You will replace the cheap shock with expensive ones after a while.
Here is the post of my shocks:
http://patrol4x4.co.za/viewtopic.php?f= ... ein#p30834
Hope this helps