[q] att sgh-i747 4.1.2 update?

I can not update my samsung galaxy s3 unlocked att phone with the applicatn the phone. I need to download the update abd manually

i need download location for att galaxy s3

4.1.2 firmware

all i can find is 4.1.1 and earlier.

Also is there a newer one after 4.1.2 thats not 4.3.i have read there are lots of probles with 4.3 is that true still??


Thank you for all comments, ideas and links!