I used custom steel wheels with baby moons on my teardrop. The critical items are: (1) wheel center diameter - it must be large enough to clear the outer bearing end and grease cap of your wheel hub, (2) offset/backspacing, and bolt pattern.
Offset and backspacing are not the same. Offset references the the distance from the center line of the wheel. Trailer wheels usually have 0" offset. So a 6" wide rim with 0" offset will the mounting surface/flange of the wheel in the center of the wheel width. Automotive wheels usually reference backspacing. Backspacing measures the distance from the inside surface of the rim to the mounting flange. With backspacing you have to consider the thickness of the wheel where the bead seats. Assuming the wheel thickness is 1/4", a 6" wide wheel with a backspacing of 3-1/4" (1/4" wheel thickness + one-half wheel width) will place the mounting surface at the middle of the wheel.
In the above example, a 6" wheel with 0" offset or 3-1/4" backspace place the mounting surface at the same location.
Note that most "stock" or aftermarket automotive replacement wheels have positive offset. If you tried mounting these on your trailer, there is a high likelihood there will be interference by the inside surface of the tire and/or wheel. I mention this so you don't pick up some automotive wheels on Craigslist and expect them to work.
https://www.wheelfire.com/blog/whats-the-difference-between-offset-and-backspacing/My 2 cents worth.
