great question but too many answers ... does it make a huge difference i.e the load of or type of trailer, i will eventually make a frame for my tub off my vehicle ( has tray now ) and it is the biggest decision which way to go with the suspension.We intend to do all hwy, track and 4wd type terrains .... looking fwd to and will take onboard all comments except "your shout" , cheers
For a DIY, leaf spring set up are often the cheapest, and easiest to get the parts to do. BUT I have found it is not all that simple to set it up for the weight of trailer, height, size of tyres, type of terrain etc.
You do need some expert advice / guesswork to get it about right.
For this reason on the last rebuild of my trailer I fitted a "Gaffa" independent trailing arm coil spring unit. Martins Trailer parts make them for Campright trailers and Pioneer. It is easy to upgrade to heavier or taller or lower springs, change the stub axle height for bigger wheels and more ground clearance etc. I did change the shocks to take bigger ones from my Patrol. It came as one complete unit all ready to bolt or weld to the chassis. Many options for springs, axles, brakes wheels etc.
If I was ever going to build another offroad and highway trailer, I will be using the same suspension for ease of fitting and upgrades.