I would suggest adding a CPU cooler. Not because you need the cooling but to reduce noise as the stock cooler can get a bit annoying IMO.
My top choice is the Cryorig H7.
http://www.newegg.com/Product/Product.aspx?Item=9SIA4UF2DZ6565
Either way, make sure you connect the fan and setup a profile (usually both BIOS and via motherboard fan software). The BIOS profile kicks in when you start the PC and the Windows profile kicks in once Windows starts to load.
Other:
Make a backup IMAGE of your SSD once you have everything installed. You can use Acronis True Image Free from the WD site to make a manual backup. Replace that every once in a while (I always keep the first one with all drivers, MS update and programs installed though).
It's pretty easy. I just choose the 2nd from highest compression profile. Backup probably not more than 20GB for a fairly new installation.
120GB (closer to 90GB with Over Provisioning) is fine for Windows and apps but I'd put your games on the HDD.
a) Install STEAM to the default c-drive location
b) open Steam and create a new FOLDER on the HDD (i.e. "E:\Steam2")
c) when installing games choose the HDD folder