Enclosed Trailer Question

So my kids are School of Rock kids and are always playing with a band and we have all the sound equipment to haul around. That would be the "primary" use for the enclosed trailer I am considering. BUT! Since I go to rides all the time and don't always ride the bike (cause I don't want to wear out my knobbies) I have been known to trailer my bikes. I usually have friends and family in tow. Normally or Ideally I would like the ability to bring 4 full size motorcycles. My wife and I both have DR's and two of my ridding buddies also have DR's, so all that to get to the question...

What size enclosed trailer does one need to possess to haul 4 DR's strapped securely with gear in an enclosed trailer. Pics?? and Opinions??

You're probably gonna want a 6x10 at minimum. 6x12 would be even better. I used to use a 6x10 as a race trailer years ago... worked great! I had four wheel chocks set up in it at a 45 degree angle, super easy to roll in and out.  A V nose is a great option to have - you'll get 'free' sqft for gear and stuff there. Also, I'd get something with a fold down door you can use as a ramp.. that makes loading incredibly easy.

My mom has a pretty big enclosed trailer for sale. I'll try to get some pics of it if you're interested?