As someone who build a system several months back on my own from ordered parts, maybe I can offer some useful insights.
From what I can tell, your rig will work perfectly fine for most games currently on the market. In fact, considering you have an SSD I'll bet your Windows Experience Index is well above 7 (out of 7.9). Personally I'd not use Windows 8.1 (Win7 fan) or pay for an antivirus, since Avast kindly provides a year's worth of service in exchange for an email (don't use your actual email, just cause), but in the end it's your money and thus, your choice.
The SSD may require some maintenance; I know for a fact that Windows 7 turns off automatic defragmentation for SSDs, however I would still check that your system does not do that, it's pointless for SSD and it wastes precious write cycles for storage cells. Go to 'C:/Windows/System32/dfrgui.exe' and run it. That should open up the graphical interface for Disk Defragmentation Utility. From there, press 'Change Settings' and in the window that pops up, ensure that your disk C and your System Partition are unchecked. If they are checked, uncheck them and press OK.
There is an armada of tasks you can do to increase the life of your SSD, but as much as I'd like to help you I cannot since I don't own Windows 8.1.
Google can help though.