this system should be a hybrid crossfire, with kaveri technology they can work with R7 240 & R7 250 with ddr3/ddr5 memmory. I picked r7 250 for maximum potential hybrid crossfire, I changed your ram in to 1600mhz, you really cant see their difference in this low type of rig, I picked antec vp 450 for hi quality atx standard, I picked the cm haf case for the best airflow case on your budget