[New System Build] Budget Desktop $400-$500

Hello all, I am currently putting together a budget build and would like some advice on whether or not i should go with the build i am currently thinking about. everything is from newegg minus the ram so far.

This computer will be a Windows 7 machine that i wont be gaming on, i do a lot of multi-tasking, and a decent amount of photoshop but nothing too complicated. I would like to keep the build at around $400.00 (i can probably live with a little over that), and i dont need any of the peripherals (i.e. monitor).

[CPU] - AMD Athlon II X4 620 Propus 2.6GHz 4 x 512KB L2 Cache Socket AM3 95W Quad-Core Processor $99.00

I went with this processor because of the fact that it is a quad core for 100 bucks, figure for what i want it should be good.

[MOBO] - ASUS M4A77TD Pro AM3 AMD 770 ATX AMD Motherboard $89.99 ($79.99 after MIR)

This mobo supports DDR3 and is not very expensive and has gotten good reviews so it seemed like a good choice.

[GPU] - SAPPHIRE 100245HDMI Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 $99.99

Looks like a good video card at the price point, im sure it may be overkill for what im using it for.

[RAM] - OCZ OCZ3X1333LV6GK 6GB PC3-10666 (DDR3-1333) $80.00
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=10009748&prodlist=froogle

Pretty good price for 6 gigs of ddr3 ram.

[CASE] - COOLER MASTER Centurion 534 RC-534-SKN2-GP Black $39.99

People seem to love this case and its cheap so that a double bonus for me.

[PSU] - Havent picked one yet, i would like some ideas on this if you could.

Total so far - $408.97