Thanks for the photos, I've copied them to photobucket.
Check this link for electronic rust protection; http://www.erps.com.au/
I can't help you with prices but posting them shouldn't be a problem.
When you move the rear diff back do you move it the same distance as the second transfer case extends the gearbox, so keeping the tail shaft standard length? And what do you do to the rear shock mounts to suit the new diff position?
Tony