[1-PU70]

Shopping for a new trailer and could use some input.I will use it mostly to tow a 3500lb car loaded with cloth and stuff.Car is 15 1/2' but would like to use it for other stuff too.
1-Should I have brakes on one axel or two
2-Steel or wood floor
3-open center or floor all the way across
4-tong for 2" or 2 5/8" ball
5-16 or 18 feet long
6-What should the gross weight be, they start at 5000lbs
Thanks for any input or your opinion Thanks Gary