I would like to offer multiple flat rate shipping options:

USPS First Class w/Delivery Confirmation (US) - $3.00
USPS Priority Mail w/ Delivery Confirmation (US) - $6.00
USPS Express Mail (US) - $15
USPS First Class (International) - $4.00
USPS Priority Mail (Canada/Mexico) - $10.00
USPS Priority Mail (International) - $12.00

How can I do this with Zencart?

Thanks,

Alfred