There are a few trailer manufacturers out there. I had a South Florida trailer,(look to the left on this board) , there is also towmaster, www.towmastertrailer.com, and nexrail, and a whole bunch of others. There were several threads within the last few weeks as well that you may want to do a search on. Do you boat in fresh or salt water? Congrats on the new Donzi.
I never had any problems with my aluminum trailer, and my next trailer is also aluminium.