All you need is a 256GB SSD to install windows and have some space to install a couple games. The rest can stay on your regular drive. It'll speed up your windows, loading, and even in game loading such as dungeons in MMOs. An SSD will turn your computer into a rocket. It won't help in game FPS though, but will improve everything else.
I would hold off on the CPU for now and wait for the new AMD ZEN. It may surpass Intel in performance so don't just rule out AMD. A lot of Intel fanboys are anti AMD and tell you to just go Intel. And with DirectX X 12 games, they will be less CPU intensive so your AMD could push them just fine. It'll be more GPU dependent. I don't think it's worth upgrading the CPU for the odd game that is heavily CPU based like GTA V. That's more a case of bad game programming and not bad hardware. Some games are just hard on resources and run like shit even on good hardware and GTA V is a good example.
As for Hybrid drives there is no comparison to an SSD. Hybrid drives work good for a laptop where you only have room for 1 drive so you try to get speed and capacity out of a single drive. Fork out the $100 for a 256GB drive and enjoy the fury. I find 128GB drives just too small. By the time you install 1 or 2 games it's full. If you're the type of wierd person to have 10 big games installed at the same time and play them all then even 512GB drive might be recommended. I know one guy that has about 300 games purchased on steam and he has tons installed. He can play 50 different games in a week. Personally I install 1-3 games at a time, beat them and enjoy them then move on to something else. I usually only play 1 game at a time.
Also SSD drives are more reliable so they are a great thing for your OS to keep your windows from crashing.