It’s been a while since I brought a phone from the US, but here’s two thing to consider, is your phone unlocked from your US carrier (ATT, Sprint, T Mobile) and is it CDMA or GSM?
Delivery times depends on a couple of things; when I give the reason for transfer as Long term stay in Thailand and there’s a Thai or US holiday/weekend, it takes 3-4 days. If I give a different reason for the transfer, it’s within minutes.