I have a Swivelwheel 58DW. Use it to haul my 1993 Goldwing SE. I also installed a Rampage lift. I was using 12ft folding Black Widow ramps. The ramps are very nice, but my legs are short and wings are tall and it was still a puckering job to get the bike on the platform. Rampage takes the pucker factor out.
I can recommend the trailer. Look for them on craigslist. Be sure to use D rated tires. Also, be sure your trailer is up to the task. I recommend a minimum of 12 inch I beam.
Finally, I live in Michigan and have a Michigan "Recreational Double" endorsement. Thus I am legal in states that allow double towing with some sort of endorsement (like California). However, some states forbid double towing (basically east of Ohio). I have not heard of a single person that has something like these platforms have any problems. In fact, those that have used them, have said they have had no problems. HOWEVER, that doesn't mean some LEO with nothing to do, will not pull you over and cause you problems. Something to consider. We have used ours locally and out west.