New/Modified Web App Pen-testing & 3D Modeling Build

[Reese]

Hello, I am building 2 new/modified rigs to help sustain my needs until I build a new overkill rig in about 6 months. I do mainly Web app Pen-testing for bugs, AOSP dev pen-testing for bugs, and 3D modeling for designs for my 3D Printer, and also some music production in FL Studio. I already have about 12 GB of DDR3 ram, 1 1tb 7200rpm hdd, 2 AMD 3/3+ socket motherboards, my graphics cards suck so ill be replacing those, and I do have 1 AMD FX 6 core cpu for one of the motherboards. I would like both of the builds to be pretty similar in specs/power. 

 

Not sure if should go xeon for one of the builds or both, if not I would need 1 more amd cpu or just replace those with intel ones. Not sure. As far as gfx go, i'm not too sure what is in this price range as used go on ebay since I will be doing some 3d modeling, both computers powering at least 2 1080p monitors at once. 

 

I'm not looking for anything too overkill, as I am on a pretty low budget of $200 max, so I will be buying used parts. Just trying to get an idea of what I should look for when I go shopping.

 

Thank you for the help