Love my kendon, it's an open trailer but stores anywhere and is a breeze to use on those rare occaisions and easily hauls two bikes. And easy to load one bike by yourself, i acn load mine in about 3 minutes. If you got the $$ and space to store one, enclosed trailers are nice, just something I could never afford.
I like the open steel trailer myself. It's easier to check the load and easier to load and off load. Here's a link that will assist you it lashing the bike down. (the link below suggests to compress the rear springs--I haven't thus far and haven't any drawbacks for not doing so. Power sport outlets are your least expensive place to get all the required tiedown materials with Lowes being the place to get "D" rings and grade 5 bolts for mounting the chock. http://www.canadianrider.com/articles/tiedown.htm
Gotta say wrapping the triple tree on each side with two soft ties and the left rear foot peg mount on a dyna is a snap. The right rear foot pegs takes a bit of thought. Once I put the soft ties on, I put "D" rings on the so I can hook both ends of the ratchet strap onto the "D" ring. PM me and I'll send you some photos of how to tie a dyna down on an open trailer if you need some help with it. (you see, I got this plan to take it somewhere this Winter for a project and thought its better to figure this stuff out in warmer temps than messing with it when it's single digits)
A used horse trailer works great. If you look around, you can find one with a ramp and maybe even a storage area. Remove the divider and you can haul two-three bikes, no prob. They usually have large wheels too.
Couple of things on trailers, Horse trailer I do not believe is a good idea for a couple of reasons,they are of steel construction which makes them to heavy, i feel that they are to big to be pulling down the road for one or two bikes. With horses in the trailer you will want electric trailer brakes, bikes weigh nless then horses but with the weight of the trailer you may still need brakes. The horse trailer also may limit u with the type of vechicle you can pull it with.
I used to have a kendon trailer and liked it. It was good construction easy to tow and moveable by hand with bikes loaded on it. I also liked being able to store it in the garage when not in use.
Renegade Ranace makes an inclosed trailer that is aluminum, lightb wieght, large tires, and you can get them in different sizes. I have one that holds three snowmobiles or four bikes. The prices I find to be reasonable also. One thing to keep in mind is to get a trailer with easy-lube hubs so you can grease the bearing with out pulling the tire off.
I had a one bike Pace in 5x8. When I went to 2 bikes so I could bring wife's Sportster (when she flew in to where I had a TDY) I started looking. I wanted 1 axle to make it easier to push myself when off the car.
Narrowed it down to a 7x10 Well Cargo. Not cheap, but I can put 2 bikes almost side by side. Shorter trailer and 1 axle.
Notes; make sure you get a ramp door and extra height (makes it easy to ride in), Make sure your vehicle can handle 7 pin wire/plug and get electric brakes to help stop the thing on I-?? in the rain. Understand mileage will go down the crapper. And think about how you want to secure them--I use "wheeldocks" so I don't crank down the front forks, and Silk rear wheel chocks to keep the back end from sliding around. I put these small chrome rings bolted to the bottom of the shocks in back and pull tiedowns to floor near front and 1 1/2ft off center to keep bike in front chock and from rocking into each other. Your call on vents, I put vents in side (left-front/right back) to keep inside cool.
I like my Kendon single bike trailer. It's all I could utilize since I had no outside storage available and I can store this one upright in about a 2x6 footprint in the garage. It was really my only option for hauling between AZ and NY when I was a snowbird. Now that I'm in AZ year round, I keep it for potential emergencies.