What to use as a shipping box for Rel storm II

Don't know where you're located, but look in the yellow pages under packaging materials and find a full-line supplier. There are many standard box sizes that will work, add 4" to each dimension and pick the closest one. Look for at least a 200# carton, preferably 275# doublewall. Then get a big roll of 1/2" thick bubble wrap and start wrapping til it fits. Probably cost around $40 total. BTW, these subs are supposed to be shipped upside-down, so remember that when you put the address label on.

One more thing: the strip-mall joints (Mailboxes Etc, etc) are a gigantic ripoff, you will literally pay between 2 and 3 times as much there as at a commercial shipping supply. This is also true of their UPS rates vs actual UPS rates, so beware! They are counting on your ignorance to make a killing.