Storing Images: MongoDb vs File System
MongoDB GridFS has a lot of advantages over a normal file system and it is definitely able to cope with the amount of data you are describing as you can scale out with a sharded mongo cluster. I have not saved that much binary data in it on my own but I do not think there is a real difference between the binary data and text. So: yes, it is suitable for the payload.
Implementing queries and operations on the file objects being saved is easier with GridFS. In addition, GridFS caters for backup/replication/scaling. However, serving the files is faster using Filesystem + Nginx than GridFS + Nginx(look here: https://www.coffeepowered.net/2010/02/17/serving-files-out-of-gridfs/). GridFS 'slower' serving speed can however be leveraged when sharding is used