Never use USPS, personal expierience 😉
There is an Internation Priority service by FedEx.
Assuming that the rings wont weigh over 1 Kg., it wont cost alot.
I ordered an Ipod skin from CA on 2nd dec. and they shipped it with the Priority Service of FedEx, it already reached the mumbai FedEx office today. They assure fast secure service 😉 just a bit costly, but as the item you're getting shipped is worth alot more then the shipping costs, I think it will be best for you 😛
http://fedex.com/us/services/intl/priority.html
Hope it helps you deciding.
PS: USPS is basically govt. service, I wouldnt recommend it even with insurance 😉