Dell Dimension 5000 replacement PSU

I have a Dell Dimension 5000 purchased in 2005, still running Windows XP.

After it had been off for a week, I recently tried to power it up, but got only a flashing amber power button. After reading this thread http://en.community.dell.com/support-forums/desktop/f/3514/t/19456788 I tried jumping the PSU to motherboard power connector from green to black as suggested, and nothing powered up. So I assume the PSU is dead and needs to be replaced.

I have also read this thread http://en.community.dell.com/support-forums/desktop/f/3514/t/19334846 from someone with a similar problem.  My PSU model number is L305P-00 and part number 5032 (CN-0D5032-71615-513-06BE), output 305W, and it has a 24 pin ATX connector, 2 SATA connectors, etc.

I am hoping to replace the PC soon, so don't want to spend too much on the PSU. Corsair were recommended as a good brand, but they are quite expensive, so I wondered if this Novatech PSU http://www.novatech.co.uk/products/components/powersupplies/451wto650w/nov-psu500.html would be suitable? I believe they are a reputable brand. They also sell many others http://www.novatech.co.uk/products/components/powersupplies/451wto650w/ and I am not sure what the difference is between them all, apart from the power and the fact that some are non-modular, others semi or fully modular.

Would the £19.99 Novatech be good enough to get my PC up and running again, or which others would anyone recommend?