I use both Windows and OS X so I can speak from experience.
With regards to the Mac, I'm still running a 2011 Macbook Pro alongside a 2015 Macbook Pro. I would recommend them, but if all you want to do is view photos, you could use an iPad and link that to your iCloud account which I'm assuming is accessible from your Windows machine (so you can upload photos).
>>> Also when using Itunes on my windows 7 it is really slow and takes ages even to just open the programme .
Hmm, could it be indexing your media files on the first launch (following an iTunes upgrade)? If it never manages to finish the indexing (if you close iTunes), I'm guessing it will retry everytime you try to launch it...
>>> I have worked out about the word documents , excel documents on my ipad is there anything about a Mac that i wouldn't be able to do that i do on the Windows machine?
MS Office is available for the Mac. What other applications do you use on your Windows machine?