talked with a trailer company, and I figured out what I really want... air ride.
here's my current cargo trailer ... maybe for sale soon...

it's leaf spring, it bounces cause spring is 'subjective to weight'... I hate that...
any torsion bar would be 'too low' and would have put the trailer at a rake... tongue up. here is my trailer with a 45* torsion axle (lowest angle)... I know the rubber was 'aged' and it needed replaced but no one would touch it cause the body mounts were not 'safe' dimensions... I was forced to change to leaf... oh and the tires were smaller...

bottom of my receiver hitch is 21 inches high, so I do want the trailer to ride roughly the same height. I can step down on the tongue but i don't want it much lower... here's a good pic of what I mean.

so I know leaf can get me where I want... but I hate the ride, 100% beef... I know torsion can ride great... but nothing will be tall enough... unless biigger tires?? no.
so I need 'leaf' that rides great... I was thinking trailing arms... but the trailer company mentioned why not air ride the solid axle...
so... now i need to find a air bag setup for solid axles... should be easier and more cost effective.