What heatsink compound have you guys been using as a redo on the singles 
Personally, I despise thermal grease. I plan to replace the grease in my mini rigs with phase change material (PCM).
Some info:
http://www.electronics-cooling.com/2002/05/understanding-phase-change-materials
Where I buy it:
http://www.opentip.com/Electronics/Startech-Heatsink-Thermal-Pads-Pack-p-1075383.html
Also on Newegg:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835230030
Experience has led me to love PCM for CPU and GPU cooling. Never tried on an FPGA, but I'm definitely going to.
The feedback on Newegg doesn't exactly sound confidence-inspiring...