Van storage in Perth area

Hi Fellow Boggers,
We are planning to leave Brisbane in a couple of weeks for WA via the Murray River area and SA.Hope to get to the Perth area late November. We intend to look at the south west corner in Feb/March and then head north up the coast to the Kimberlys,Darwin etc.. We want to be home in Brisbane for the Dec/Jan period but don't want to tow the van all that way back for a couple of months. Could any of you friendly Boggers out there let us know of any places in the general Perth area where we could leave a 20ft bushtracker and Landcruiser for a couple of months over the coming Dec/Jan period. Obviously somewhere reasonably secure would be desireable.

Regards,
Ian & Marcia.