[Milsurplus] ? Shipping cartons ??

[Hue Miller]

Where are people going for heavy-duty, large cardboard cartons for shipping?
I live in a "town", and the scrounge-find option is not available.
I have to drive 2.5 - 3 hours to a "city" with 100,000+ population.
U-Haul ? Moving companies? Just need some preliminary ideas before i 
start making phone calls and planning the drives.  
I need cartons for big / heavy stuff such as PE-103s and  the FM for
SCR-654. ( Frame, not "Field Manual", hi. )
Thanks-   Hue Miller