Advice Needed for storage consolidation and shared access to files - 2 iphones, 1 ipad, 1 Mac and 1 Windows 7 laptop

My hubby and I are home users.  By no means IT experts but can find our way around basics.  

We've been talking about consolidating files, photos and videos for storage in one common place, with access from anywhere, and back up.  We're currently all over the place - some files saved to Windows (running windows 7) Laptop hard drive, Mac hard drive, photos on 2 x iphones and ipad, but some stuff saved to free icloud and dropbox accounts.  A bit of a dog's breakfast!

We have lots of photos and videos stored in separate places locally and in icloud, and then quite a few documents (mostly Word, Excel, PDF and Powerpoint files).  We also have personal email clear.net.nz email, as well as 2 business email accounts and gmail.  

We realise we are currently incredibly inefficient in terms of storing our files and also at risk of data loss.  Would love to free up space on our iphones/ipads, and in terms of back up we have a Seagate portable hard drive we back up the Windows laptop irregularly but that's really it.  

Considering cloud solutions which we realise can be costly in terms of ongoing annual costs, or some kind of hardware solution - eg. Mycloud - but would love to know what works best. 

Any help/recommendations or suggestions would be appreciated!