USPS but you'd have to send 2 sets of 2. Send via PMI and pay for insurance as it's cheaper.
TireRack sent my Enkei's via FedEx and it cost me $300US which included insurance and took 4 days to arrive. The FedEx option would be cheaper as the combined postage + insurance of the USPS would be more.
I want some old school fkn rims! I have to lower my sh!t first though... actually.. I have to get them side skirts on -.-" hey! sms me the person that sorted your crap out man, I wanna take it to them