Vacation in Puerto Rico and Mainland USA

Hi

I will be visiting the USA for 6 weeks & am seeking a suitable sim card & plan with data and calls.

I have 2 unlocked iPhone 4s (or a HTC Mozart). None of these phones have the 1700 band as it is not used in Australia.

Will these be able to access your 3G network?

I noticed you have a family plan (payable monthly) for $50 for the 1^st sim & $30 for a 2^nd sim card but cannot determine the total cost (fees, taxes & delivery) without providing my credit card details. I am uncomfortable with this approach until I am ready to purchase.

I could have a delivery address in San Juan, Puerto Rico or Raleigh, North Carolina.

Could you advise the total cost please?

Would you recommend any other plans? Such as Wal Mart?

Can I purchase online using an Australian credit card?

Regards DMc