try one of the amd trinity cpus i heard they are pretty good for the money
They're incredible for the money, but OP would have to sepnd a little more money for them. I thank you for reminding us of them here and I would recommend them, but they simply can;t fit in OP's budget reasonably. At best, they'd be $25 more for the CPU/APU and about $25 more for the motherboard because the good, cheap ones are all out of stock already everywhere I look.
Think you did a pretty good job. Do you really need the dvd drive? Do you have another machine with a dvd drive and a usb/external drive? That way you can save some money on that and maybe upgrade the cpu or gpu.
Asrock FM2A75 PRO4 is the choice for motherboard. Comes with everything you'll need like native USB & SATA III, support for Dual Graphics, 2600+ Dual Channel DDR3 memory (important for maximizing the power of the APU), all solid caps and all that at a great price
1)You have 25$ rebates from PSU and APU. If I were you I, with these money I would buy a heatsink in order to overclock the APU a little (although It can go easily to 4.8-5.0 GHz on air and minor voltage tweaks)