So excuse my noobness but I’m guessing I need one of the lower ones but which one if you know? I added the GP factor winch.
Look at what front springs you have now. They will have colour (color!) markings as per the above chart. If you are adding more weight you should work out the change in weight (new weight minus old weight) and go up to the corresponding amount of spring weight rating in the chart.
Example:
My vehicle was ordered with no winch and the accessory roo bar. It was delivered with green circle front springs. Another owner's vehicle was delivered with the factory winch and roo bar and it came with red circle front springs which is a +53kg rating increase (1417kg to 1470kg).
If the factory made a +53kg rating change for their winch you could also go up one rating for an aftermarket winch, unless you intend on adding more weight later then plan ahead now and look further down the chart. You only want to do this exercise once.
There should be some discarded sets of factory springs around after owners have installed lift kits. You might need to ring around some of the bigger installers like maybe AO or Owl to see if they have anything in their scrap bins.
@Krabby has been chasing some through the forum classifieds but has had no luck yet.
The pinnacle of factory springs is the purple fronts and black rears. That's the heaviest factory spring combination if you want to maximise your payload capacity (within GVWR) but avoid a heavy duty lift kit.
But if I'm being honest, whilst it still seems prudent to avoid a lift and not poke the bear on driveshaft issues, there is a growing list of driveshaft failures over stock suspension that it's becoming a moot point if a lift makes you significantly more likely to have a driveshaft failure. The remaining benefit of staying with factory springs and ride height is your warranty is unaffected. That still seems worthwhile for as long as a factory warranty remains current.
Hopefully that all makes sense!