Ahoy,
I recently just moved from california to alberta, canada. I decided after seeing what happened to my friend's PC which he tried to ship compltely assembled via UPS id never go that route.
What i did was, Took everything apart, and threw out my case. a new case costs $50 bucks for something decent and it was high time I got a new one anyways.
So im left with all the components. What i did was, I got a plastic tupperware type container and lined it with some bubble wrap. I have a 20" Dell UltraSharp lcd, the LCD itself detaches from the base which is nice, it lay nice and flat in the tupperware. I used a piece of cardboard to cover the screen itself, to prevent scratches. i put more bubbled wrap over the top. I used anti-static bags for ram, video, sound card, hard drive. I took the heatsync and fan off the motherboard (important), and just tossed it (it was oem anyways). Put the board in anti-static. All of those anti static bags i shoved into bubble-wrap mailer envelopes and sealed them. Those went in the tuppeware box as well. I closed the tupperware with everything in it, and put FRAGILE stickers all over it. and wrote "computer parts" on the top (for security just incase they dont know wtf it is). this entire tupperware box went into a REALLY HEAVY DUTY plastic suitcase. you could throw this thing off a building and it might still last. It might be hard to come acorss one of those, but do your best. I lined the plastic shelled suitcase with clothes, trustingly checked it with plenty of ID all over the suitcase and off i went on the plane. Arrived 4 hours later, got the suitcase.
Bought a new case, psu, and heatsync and fan. Everything works beautifully. No problems at all.
Hope this helps anyone out
Cheers!