Johnny, You may be able to use something like this.
http://www.timbren.com/index.htm They have been around for a while. I have not used them. However, a trailer factory in CA has been using them with composite springs for about 5 years with good success. I have ordered one of their trailers.
http://trailer1update.com/Frameless%20BD/waste3.html I am going to give it a try. If I am not satisfied with it, I will put a Neway trailing arm suspension under it which will add about 500 lbs.