First Home Build need Advice

Hello there i need some advice for my first homebuild and i don't want to mess this up xD, also need some criticisms for this. it would help alot  

CPU: Athlon II X3 440
GPU: PC HD 5770 OC 1gb ddr5 PCS+/PC HD 6850 1gb ddr5 hdmi
Memory:x2 kingston 2gb 1333 ddr3
HDD: WD 500gb SATA 3.0
DVD writer: lg 22x gh22np20 black

need some advice for the mobo,powersupply, i was wondering if the HD 5770 is better than the HD 6850. This is just for the CPU only, i'm on a tight budget by the way so it would really help if it was cheap and reliable.

Thanks,
Jes