I7-4790 runs at 3.6 stock, it can not be overclocked.
I7-4790K runs at 4.0 stock, and it can be overclocked to perhaps 4.4.
The costs are usually close, so I would always opt for the i7-4790K.
For games such as sims, mmo, and strategy games the single thread speeds are important.
For fast action shooters, the graphics card is more important.
The Samsung ssd migration app has an option to exclude large folders from the move.
You could keep them on the hard drive.
SSD prices used to be expensive. $350 used to buy you a 40gb ssd.
Today, you can buy a Samsung 850 evo 1tb for the same price.