Another option would be to look at the online configurators available from the major OEMs (Dell, HP, IBM, Sun).
Dell, HP, IBM, Sun and all other major manufacturers and re-sellers should carry 2S blade servers. Recommend you look at the Xeon 5400 processors here
HP and Sun carry 4S blade servers with intel and there are versions that support the new 6-core Xeon 7400 processors
Personally I find Dell's online configurator to be the easiest and most straight forward to navigate. Here is a link to the PowerEdge M600 Blade configurator that will show you the options and price adders for various components.