I think you are good as it is.
The current Intel cpu's have an excellent integrated ram controller. It is able to keep the cpu fed with data from any speed ram.
The difference in real application performance or FPS between the fastest and slowest ram is on the order of 1-3%.
Synthetic benchmark differences will be impressive, but are largely irrelevant in the real world.
Fancy heat spreaders are mostly marketing too.
Only if you are seeking record level overclocks should you consider faster ram or better latencies.
Read this Anandtech article on memory scaling:
http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3/1