[mikeinatlanta]

Regarding moving with it.

IF your trailer is like almost every other trailer out there, you will overload it moving by weight long before you run out of volume. Unless you are stepping up to bigger axles, a longer trailer will actually move less than a shorter and lighter trailer of the same construction.

EG. The manufacturer of my 18' puts the same axles under their 16', 20', and 22'. My 18' weighs 3,000, so I'm only good for 4,000 of load. It doesn't take much stuff to blow right by a 4,000lb load. That said, I'd get what's needed for the car without consideration for moving.