Noob need help in choosing PSU

Please help me, i can't decide which PSU to choose.

My build is:
E7400 - planning to overclock
P5Q SE2
Kingston 2GB 800 ddr2
Kingston 1GB 800 ddr2
Seagate 500GB
1 DVDRW
500w Generic PSU - came with the casing
90mm case fan x2

i'm going to add a power color HD8450 next month and from what i have read from the other thread my PSU is not enough.

the only choices I have here are:
ACbel Ipower 660 - 74$
ST50F - 78$
ST60F - 150$
Cooler Master 550w - 104$
Odin pro 550w - 110$
Corsair 620HX - 138$

Thanks in advance!

or corsair 620HX

thanks for the replies, the 620HX and odin pro 550 are pretty good looking specially the latter, but do i need high wattage PSU for my setup?
i was leaning on st50f (very cheap) and odin pro 550 (for the looks)

then i will be getting a st50f, thank you for the time.