new build Is This Compatible, PSU and GPU Change

Current Specs

GIGABYTE M68MT-S2

1 x PCI Express x16 slot, running at x16
2 x PCI Express x1 slot
1 x PCI slot

1 x 24-pin ATX main power connector
1 x 4-pin ATX 12V power connector
4 x SATA 3Gb/s connectors
1 x CPU fan header
1 x system fan header
1 x front panel header
1 x front panel audio header
3 x USB 2.0/1.1 headers
1 x parallel port connector
1 x clearing CMOS jumper

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PSU = WinPower 450W Power Supply

Details - Support for the Latest Technology - Intel Core 2 Duo and AMD Athlon 64/64FX support aswell 8cm Black Fan Separate 12V rails - Independent 1V rails meeting UL 240VA Safety Requirements High Reliablity - OCP, UVP, OVP, OLP, OTP AND SCP circuits to ensure system s Specifications Approx Dimmensions Length 160mm, Height 90mm, Width 140mm Retail boxed Manufacturer: Winpower 1 x 20/24 Pin Main Power 1 x 4 pin Main Power 1 x 4-pin floppy 1x SATA Power 4 x 4-pin peripheral

I WANT TO REPLACE WITH THIS PSU ********************************
Antec NEO ECO 520C 520W Continuous Power ATX12V

Spec:
Type ATX12V v2.3 / EPS12V
Maximum Power 520W Continuous Power
Fans 120mm Double ball bearing fan
PFC Active
Main Connector 20+4Pin
+12V Rails Single
PCI-Express Connector 1 x 6-Pin, 1 x 6+2-Pin
SATA Power Connector 6
Efficiency > 80%
Energy-Efficient 80 PLUS Certified
Over Voltage Protection Yes
Input Voltage 100 - 240 V
Input Frequency Range 50/60 Hz
Input Current 8A @ 115V, 4A @ 230V
Output +3.3V@24A, +5V@24A, +12V@40A, -12V@0.8A, +5VSB@2.5A
MTBF >100,000 Hours
Approvals cUL,TUV,CB,CE,FCC,CCC, C-TICK,BSMI
Dimensions 5.9" x 5.9" x 3.4"
Weight 4.0 lbs.

1 x Main connector (20+4Pin)
1 x 4+4-Pin ATX12V/EPS12V
6 x Peripheral
6 x SATA
1 x Floppy
2 x PCI-E

Want to replace a ATI Radeon 5450 for a ******************************
Gt 620

http://www.geforce.com/hardware/desktop-gpus/geforce-gt-620/specifications
specifications there



IS THIS COMPITABLE ! ARE THE TWO SWITCHES OK?