I'd suggest two things.
1. Redundancy. If they're really important, you need to have at least two backups, ideally in two different locations. i.e. an NAS and cloud storage.
2. Long term needs. If you're just looking to back up jpegs of family photos, the solutions you're looking at are just fine. However, if you're thinking about getting into serious photography, neither of those would be adequate. You'd want to get a higher quality NAS with at least 3 bays so you can run raid 5 (I think it's 5, the one with distributed parody information) and a more robust remote backup service.