After you get your new axles, springs, tires, wheels, get your trailer aligned. It's absolute amazing how many trailers don't have the proper alignment. It's usually more expensive that having your tow vehicle aligned, but is worth it in tow-ability, wear on tires, and peace of mind.
And you might have a good talk with the people who install your new equipment. Make sure you tell them that they MUST install this with CORRECT ALIGNMENT. Amazing how many just don't do it. And if they tell you they can't check the alignment, get the work done where they can do the alignment. Don't take NO for an answer.