Model A and a trailer

[springerpete]

As a kid I remember my father's teardrop trailer that he and my grandfather built in the 30's. He did originally pull it behind his '31 roadster. I would like to build one as a winter project but wonder about a lot of things regarding Model A's and trailers. My tow car is a 29 roadster which is a good stock, restored car. So here goes:
1. What total weight should I limit the trailer to ?
2. What would be a good "tongue weight" ?
3. Electric trailer brakes a must ? Do they come in 6 v ?
4. What are the best methods of fastening the hitch to the A's frame ?
5. I'd like to use a Model A axle for the trailer so I can use 21" wheels
and tires, how does this play into question # 1 ?

I appreciate your help with any thoughts or links to things in this area. Bill