My last frag pack was was shipped from Kansas City and arrived in perfect condition. Each SPS frag was mounted on a plug and labeled. Each plug was tied to a piece of styrofoam with a rubber band and then each piece was double bagged. Several bags were then placed in a large ziplock. Finally, everything was placed in a foam lined box with a heat pack and shipped FedEx overnight w/Saturday delivery. Frankly, if it were me I'd insist on FedEx overnight with buyer paying all shipping costs and delivery signature required to ensure that the frag pack doesn't sit on the porch all day. You'll avoid a lot of "all the frags are dead" emails that way.
Good luck,
Mike