I haven't fully set up a list of power supplies yet, so my apologies for not being able to recommend something cheaper. This PSU will do a significantly better job than the one you linked. (the website is a price aggregator for vendors). At the best price, it's also cheaper than the one you linked. It's a Tier 2a 550W Bronze Certified Power Supply for $55 ($45 on promo), with 44A on the 12v rail.
http://pcpartpicker.com/part/xfx-power-supply-p1550sxxb9
When upgrading a system for gaming, the first thing you upgrade is the power supply (PSU). If you try upgrading a performance part (CPU/Graphics) before the PSU, the old PSU will explode. The primary ability of a PSU that you are looking for is not Wattage (i.e. 450W vs 550w vs 750W)...