The latest from Mark at Flex-form:

Hi Justin,

We have always shipped air parcel service because there hasn’t been a cost advantage for ship-based for a single package. 5 sets may be a different matter, I’d just have to check it out to see. We pack them so that the parcel length is about the same as the spring length. Use about 19 pounds per pair for a weight estimate.
Spring rates for monoleafs in general and especially for composite monoleafs is different in that eliminating the friction between the leafs and changing the material makes them feel like lower rate steel multi-leafs. Most springs we’ve made for vehicles like yours have been in the range of 175 to slightly over 200 lbs/in.

Mark