Is this a good 600$ gaming build? any i can improve on? 600$ budget

[Bone145]

CPU - AMD FX-6300
Motherboard - ASUS M5A78L-M LX PLUS AM3+AMD 760G Micro ATX AMD Motherboard
Video Card - VisionTek Radeon R9 270X
RAM - Kingston Hyper X Blu 8GB
HDD - Seagate Barracuda 500 GB
Case - NZXT Source 210 White
Power Supply - Antec VP-450

New to building a computer , is this all the parts i need? (aside from the os,keyboard,mouse,monitor and optical drive) , will i need to replace the power supply? since the R9 270X required a 600-750w and if there are less expensive parts yet better , i greatly appreciate it.
Thanks

 

[veladem]

How bout this if I can sway you?

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($117.12 @ OutletPC)
Motherboard: ASRock 970 Extreme3 R2.0 ATX AM3+ Motherboard ($79.99 @ Newegg)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($64.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($59.98 @ OutletPC)
Video Card: PNY GeForce GTX 760 2GB Video Card ($236.98 @ Amazon)
Case: NZXT Source 210 (Black) ATX Mid Tower Case ($29.99 @ Microcenter)
Power Supply: XFX 550W 80+ Bronze Certified ATX Power Supply ($25.99 @ Newegg)
Total: $615.04
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-02-23 00:21 EST-0500)