You are on the right track, I'm however going to suggest the following.
Drop the G4500 and get a i5-6500 or i7-6700
http://www.gtxgaming.co.za/index.php?route=product/product&path=73&product_id=173
http://www.gtxgaming.co.za/index.php?route=product/product&path=73&product_id=139
You can drop the fancy cooler and get a cheapie seeing as you are not overclocking and these cpus don't really run that hot under load. On the hottests days here I hit about 70C which is fine.
Drop the 120GB ssd as it's tiny and you are not gonna fit much on there, when you have money in future get a 256/512GB ssd. Just used the hdd for now.
Get 1x8GB stick of ram instead of 2x4GB seeing as you only have two dimm slots and in future should you need more ram you just pop another 8GB in there and you dont have to faf around trying to flog the 2x4GB stick in order to upgrade to 16GB.
Do you need a optical drive, things have become pretty redundant if you ask me.
If you have to buy a gpu now rather get a secondhand gpu off carbonite, you can get something more powerful for way less money.
Thanks for the advice. I see your point regarding the CPU Cooler and RAM, both valid. I think the SSD is a good idea, as it's just for OS usage, not storage, though honestly I have no idea how large a Win 10 installation is.
On the GPU, I guess I'm a little leary of second-hand, likely overclocked GFX. Sudden death is not a game I enjoy and as much as I enjoyed National Treasure, artifacts just aren't my thing.