Hi, On a s/775 you will need to really work your grease down around the pins gently so as not to bend them...I would get Lubrex with the small tip so you can get around the pins easier.Luberex Dielectric Lubricant
..Basically you use conformal around your socket and on the back of your mobo around the socket area...Seal around the base of your socket with either silicone,I've used Permatex Hi-Temp RTV sealant or Liquid electric tape for that...Then pack your socket with grease, cut some neoprene out to go around the socket then a piece on the back of your mobo to and neoprene all around hte bottom part of your block, you don't have ot do the top...Be sure to crush your TEC when you mount it ot your block it will give you a lot better performance,I use a big C clamp to crush mine with i'll leave you a pic..I get most of my condensation proofing stuff at DD..Conformal
...... Dielectric Grease
Here are some pretty good links and I'll leave you a couple of pic's to..Hit my camera icon and go to my gallery also I think I still have some more condensation pic's there to...
...Pelt Condensation Proofing (out-dated but good)
...Cold Plate Materials and Thickness