I guess you have to narrow down a few things.
Do you want the trailer more for sleeping or for bike storage?
If your just looking for sleeping, then you may be able to find a cheap pop-up that you can trail behind your truck and throw the bikes in the truck bed. Or you can step it up and get something like Chickenhauler, alot nicer and still more affordable than a toy hauler. If sleeping and creature comforts are your main concern.
If your more concerned about loading all your tools, bikes and gear, I would lean towards an enclosed. We used a 5x10 for the last 10 years, I built some shelves and outfitted it more for bike storage. We slept in a tent most times, but if it was too wet, we were able to lock the bikes outside and throw a mattress on the floor of the enclosed and stay alittle warmer and dryer.
For me, I love the enclosed. I love being able to carry spare parts for the bike, my tools, gear etc... and when I get home, just unload the bike and park the trailer till next weekend. Love it so much, we outgrew the 10' and I'm currently (slowly) working on setting up my new 20ft enclosed to be alittle more comfy. I've got 12' outfitted for a garage and 8ft plus the small wedge nose set aside to build some bunks and "home" storage.
Ultimately, if I stay at this long enough, I'll get a toy hauler. But, financially it won't happen for prob another 10 years. too many other things to keep up with. Until then, this 20' enclosed is going to get some use!!!
There's also the Hobby style trailer where you can fold bunks up and roll the bikes in the middle. I personally don't like this. I would rather have the bikes seperated at all times from the living area. Just my preference, as I have friends who have a hobbie style and they love it. For me, I want to keep the clean area clean and the muddy area muddy! ha!
Good luck.