Looking for some suggestions on new hardware

Heya everyone. Lurker here finally deciding to stop being lazy and start actually posting on this forum. So, my first order of business is to ask for some suggestions for new hardware. My PC is getting a little out dated and needs an upgrade, and me (being the indecisive little idiot I am) can't decide on new hardware. The current rig is as follows:

CPU: AMD FX-4100 @ 4.2GHz
RAM: 8GB Corsair HyperX Blu @1600MHz
Mobo: Asus M5A78L-M LX Plus
GPU: Radeon HD 6870
HDD: 1x WD Caviar Black (1TB), 1x WD Caviar Blue (500GB), 1x Seagate Barracuda (500GB)
PSU: Corsair CX600M
Optical drive: Don't have one. Suggestions please.

Now, I love this setup and it will run just about anything at max settings with no problem, but there are things starting to come out that my system can't handle. I'm mostly looking to upgrade just the motherboard and the graphics card, but if there is something in here you feel just HAS to be replaced, let me know. I'm looking at a budget of about $300 right now to replace parts. I would prefer an AMD CPU, but I'm open to suggestions on Intel. I will NOT use an Nvidia card, so please do not suggest any.

Second order of business is that I can not, for the life of me, figure out how to set up a signature. If anyone can let me know how, it would be greatly appreciated.

 

To edit your signature click on Settings in the top-right corner of the screen, and on My Settings under My Profile click on Edit Signature.

 

If you want something that will be better suited for BeamNG, I'd suggest an i5 or i7 haswell processor. Those seem to be best for running the game in it's current state.

 

Suggestion 1: Ditch that board and CPU and get an FX-6350 and a better board and overclock the CPU
Suggestion 2: Get an AMD R7 260x (budget) or an R9 270
Suggestion 3: Forget the optical