i like the trailers from Costco that are made by Stirling. I've had 2. I replaced the first one i had with a newer model because I saw a lot of improvements in the design. you can get them elsewhere as well like at Rona, sometimes home depot, etc but for a tad more money. There are two widths, 4ft and 5ft, with an extendible front end. Go for the larger width. More room and easier to see it while you're driving.
You definitely want sides, a tailgate that doubles as a loading ramp and can support up to 900 lbs. Mine is all galvanized, but the hardware like hinges etc are not, so make sure they get a good dose of rust proof spray or wd40 at minimum.
Not much more I can think of at the moment, but that should get you started.

  i kind of like the 33 foot trailer sleeps 6 and has a furnace and A/C
 
or are we talking 2 different types of trailer?
 
HunterPower

RR, I  would not have bought a 2nd had they not made the appropriate improvements. Better tailgate, better locking mechanism that hold the sides in tight, and fenders mounted directly to the side without a bracket are the major differences. Have a look at a newer one. I took it as they saw where they needed improving, and made the changes. I'm very happy with my new version of the sterling trailer. Had I not seen these changes I would have gone with another brand.
 
Hunterpower, that works for me too, is there room for an ATV though? laffin.

  Hello BE, since this is a hold over  until you get your truck you might want to check out a used one.

 
Location - Peteboro
 
http://www.thetrailerdepot.com/trailers.php

i hope they have made improvements. I hope they changed the spindals to a real axle too. I did write them some letters on the trailrs and how they could improve them. They sure didn't seem to last when you put milage on them. I'm real happy with my single snowmobile trailer and sure wouldn't go back. It wouldn't even hold a skid of bricks which was below the max weight.
 
RR

No I now just use the single sled trailer for a snowmobile only. When I had an Atv I used a double snowmobile trailer and usually hauled around two Atv's. The only thing is sometimes I used ramps only because it could be hard to tilt the trailer back up when there were two. The single I have now has the road clearance that the Sterling didn't. The sterling never really fist my Tundra 300 properly. I had to drop the front deflector so I could move it far enough forward. When I left the rear ramp out to give you more room it was only about 4" from the ground. Also the license plate was hidden then. The failure seemed to be constant with blowing tail lights which were sealed. The fenders not only fell off but they were constantly comming loose from the main bolt.
 
 
RR