PSU upgrade for Inspiron 530S

[mister g]

Hello, TH. Anyway my little brother has a Dell Inspiron 530s slimline pc. I plan to get him a radeon hd 5570 when it gets to my local MicroCenter. The one thing I'm worried about is his 250W PSU that came with his PC. I'm running a an HD 2400 I got him last year on it right now. Most people say a Seasonic PSU should be put in but its not available in the store and I can't buy online (no credit card). I've been planning to get this:
Athena Computer Power: Apollo 400W Micro ATX PSU
http://www.microcenter.com/single_product_results.phtml?product_id=0318679
Do you think it's any good?

 

[delluser1]

Most people say a Seasonic PSU should be put in

Not only due to the brand name , but because it's the right type of power supply
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151090

 

[mister g]

Really, I thought this would work, I measured it based on the specs and it would fit.

 

[mister g]

I looked at the product both on Newegg and on Seasonic's website, thank youu for your input. You don't need a new name, you can help out a lot of other people just like me.

 

[mister g]

Best answer selected by mister g.