Your computer does not look very power-hungry; as a matter of fact it looks quite similar to my Celeron D system--and it came with a 250W PSU. Go figure.
But I digress; I am quite happy with my Seasonic S12-330, which can handle 330W (supposedly but I think it can handle even more). If that's iffy, go for S12-380, which is--you guessed it--a 380W power supply.
Antec SmartPower/TruePower works as well, but it will be slightly less efficient and a bit louder.
I advise you to stay away from Rosewill--they have poor efficiency and will heat up your room. Good in winter, bad in summer.
As for other brands, I have no experience and hence I will not make any recommendations from them. However, FSP Green PS FSP400-60GLN sounds very good to me. Just stick with name brands and don't waste your money going overkill in wattage department. 400W would be as far as I go; 450W if it is a bargain and is something I can trust.
The Fortron Source 300W power supply goes for as little as $22 and is more than enough for your system. I was just testing one on an overclocked P4 530 at 3.8GHz with two 6600GT cards in SLI mode, and it could game for, oh, like 20 minutes before lockdown.
BTW, that system would be pulling twice the load of yours.
I have had a Seasonic S12 430 in my computer for almost a year now and I would recommend it to anyone needing a power supply. It is very efficient which cuts down on the heat produced and lowers your electric bill. A by-product of the efficiency is low noise as the fan speed is temperature controlled. The unit is much quieter than the Sirtec one it replaced. As you would expect from a quality manufacturer the voltages are rock steady and the amp and power ratings are not inflated, you get what you pay for with Seasonic. Now if I can just do something about that NForce 4 fan the PC will really be quiet.