Regarding HIPAA and SQS: although your BAA with AWS probably does not allow you to use SQS for PHI, it probably allows you to use S3 (but don’t take my word for it, look in your BAA to be sure).
If so, you can put your payload (PHI) in an (encrypted) S3 file and send an SQS message that refers to the S3 key. When you process the SQS message, you can take the S3 file and process it by deleting the message and / or file as needed.
There is even an “advanced” SQS client that you can use to handle this magic for you.
S3, , . , , . , , S3. PHI S3, BAA SQS.