I have a 6s, rMBP and soon to be iPad Mini 4. I have all of my photos synced to iCloud and pay for the 50gb a month option. This allows me to store a lot, and also sync to my rMBP. I will be buying a 16gb iPad, as I have no need for the 64gb version. Will I be able to sync only my photo stream from my phone (so it only syncs the last 30 days worth of photos?) rather than my whole photos collection?