I'm sure you'll get lots of recommendations for specific brands of hitches, etc., but if you're looking to develop a better understanding of trailer stability and sway cause/effect...
I'm learning a LOT from a thread I started about weight distribution.
My original question was specifically about tandem axles, but the principles being discussed apply to all towing.
Lots of folks that know their stuff have "weighed in" (
) with information.
I've learned more about Applied Physics there than I EVER picked up in school!
You might want to take a look:Dual Axle Trailer Tongue Weight
Hope this helps!