brakes needed on a enclosed trailer with cycle in it?

Forget about the state laws. It just makes sense to have brakes on a trailer of that weight. Even if the state law allows for no brakes on that GVWR. Just get a trailer with brakes. It's the right thing to do. Maybe you don't need them. But they aren't going to hurt anything. And I'll bet your tow vehicle brakes will last a bit longer too.

So buy the trailer with brakes and don't worry about the laws. Protect your cargo with the best you can. The only laws you need to worry about is the laws of physics. And those indicate you should get brakes on that trailer. And those laws always trump state laws.