[http://www.performance-pcs.com/water-blocks-cpu?dir=asc&order=price[/url]
This isn't filtered by socket since many blocks will fit multiple sockets, but just about everything on the first 2 pages that will fit your socket would be a decent choice. The Phobya blocks are on the cheaper end of the scale and would be alright if you were really looking to stay budget friendly, but there are also some well-priced EK and AquaComputer and Watercool blocks that are only a few dollars more which are typically better made products. Regardless, just about every block listed will keep you within 2-3C at load of any other block for the most part, assuming your install makes good contact with the CPU IHS and you use decent thermal paste and good application.