Case is looking good for that price, good feedback on neweeg.
HDD spot on
MOBO is not too good even tho it's cheap the PCIs are at x16,x4 and thats not good. You should spend more money on MOBO as it's important part of a new rig.
This MOBO would be better:
ASUS M4A89GTD PRO/USB3 AM3 AMD 890GX HDMI SATA 6Gb/s USB 3.0 ATX AMD Motherboard
(ASUS is high quality brand so nothing to worry about with that. And also this MOBO is capable of Crossfire at x8,x8 wich is good.)
GPU looks ok if you looking at gaming at lower resolution or with higher resolution but med-high setting.
PSU: dont know much about how good antec is at PSUs but i know antec does a very high quality Cases. ( othervise yes 650W is enough)
RAM: Dont know about that brand but it has a very good feedback saying ''they are amazing''.
CPU: For the price this CPU is lookin good, has a very good feedback is well. Also you can unlock the 4th core wich the MOBO i showed is capable of doing.
And now the built looks great to me.
Also have you considered going for gtx 460 or ATI readon HD 6850?
I am not the best with MOBOs so daves suggestion would probably be best.
The CPU, GPU, and RAM, could a few suggestions.
First off, I suggest that you look into a Phenom II x3 740. That CPU is a Phenom II triple core (with the possibility of being a quad-core) with 6MB of L3 cache and it has a pretty good performance increase over the athlon. And if you are able to unlock the 4th core, you could have you like a Phenom II x4 945, which is like a $140 cpu.
Also look for combo deals when buying parts, i save nearly $70 buying my parts in combo. I got a corasiar PSU 850W and G.Skill 4gb ddr3 1600 for $190 compared to $230. I also found some other combo deals as well, but i would recommend that before purchasing and not saving $$$.
I don't suggest upgrading to a Phenom II X3 or X4, well maybe the Phenom X3 740, but not the X4, reason being. If you can keep your budget as low as possible. Do it. The Bulldozer series is coming out next year for AMD and that'll be a new chipset (AM3+ or AM3r2) however you want to call it, it'll be better and faster. So if you save enough money on this build, just keep upgrading through the course of the years. I mean expect Bulldozer to be cheaper since SB (sandy bridge) seems like it'll bulldoze bulldozer, so... Yeah... just my 2 cents.