For the purpose of applying for Portuguese citizenship, birth certificate are valid for 6 months and FBI reports are valid for 3 months
US birth certificate
A certified US birth certificate can be ordered online here
https://www.vitalchek.com/birth-certificates
How to order the birth ceriticate online?
FBI report
It is not recommended to issue FBI reports directly from the FBI as it takes 3 months to arrive. It is highly recommended to use an FBI-approved Channeler, which takes 7 business days to issue the report.
Such a channeler which our clients have good experience with is
http://www.myfbireport.com/
How Do I Get FBI Criminal Background Check Done fast?
Apostille
Both documents, before they are submitted to the Portuguese government need to get an Apostille
Our clients have good experience with these companies that provide Apostille services