Hey,you will be surprised to see how much you can get onto a pickup truck if you planit a little... and then you will have to make only 1 trip to the field....
I have the same problem and is thinking of getting an i.e. standard2.4 m trailer - no need for a customized thing,You can get a lotin there without too muchexpense.Maybe fit one of thoseslide windows in the backof the cab?
Cheers
Bundu