Red Hat and IBM have teamed up to make some high performance Nodes.  These systems can be either Power or x86 systems.  IBM also recently announced their Pure Systems and Pure Application lines of systems.  These are pre-built systems with everything built, tuned and ready for your applications.  You get the benifit of having IBM’s team of specialist build up and tune the systems for you which is great for time crunched projects.  IBM of course charges a premium for the systems but they configurations are very flexible. You can check more on the PureSystems here.