Sanity check for building a C6100 for low power/heat/noise

[idea]

Hey everyone, I am looking for advice/sanity check on this project.

My goals are to build a C6100 with:

1. VMWare ESX cluster lab with VERY low utilization
2. As quiet as reasonably possible
3. As cool as reasonably possible
4. As energy efficient as reasonably possible
5. Spend as little money as reasonably possible
6. No hacking the case, splicing cables, power tools, etc etc.

What I currently have to work with:

1. DCS C6100 chassis (PIC16 FCB) with 4 L5220 DCS nodes
2. Non-DCS C6100 chassis (PIC18 FCB) with 4 E5520 non-DCS nodes (upgraded all BMS, BIOS, and FCB to latest firmware)
3. 4 quieter Supermicro fans
4. 4 sets of 5pin to 4pin fan cable adapters (for PIC16 FCB)

What I think I need to do to make the chassis quiet:

1. Insert the 4 non-DCS nodes into the older DCS chassis (just so I can use it's PIC16 FCB, because I can't find a good solution for PIC18 adapter cables)
2. Swap out the stock fans with the quieter Supermicro fans
3. Sell the 4 DCS nodes and the non-DCS chassis, I don't need them anymore
4. Enjoy a quieter-than-stock C6100!

What I think I need to do to make the nodes low power/low heat:

1. I have 8x L5520 (60w TDP) and 8x E5520 (80w TDP) to work with, HOWEVER:
2. I think I want to buy either one X5650 (95w TDP, six-core, 32nm) or one L5639 (60w TDP, six-core, 32nm) for each node. The prices on these have been falling lately.
3. Only run one of these per node. I don't need dual CPUs per node. If I ever changed my mind in the future, I could simply pop in more CPUs
4. C6100s will work with one CPU per node, but I cannot use the 6 DIMM slots next to the empty socket (reference: http://www.servethehome.com/answered-cpu-dual-processor-motherboard/)
5. Sell the 8x L5520 and 8x E5520 on eBay. I don't need them anymore.