If you had a difficult time installing the Alpha, I would carefully research the MC462 before I purchased it if I were you. You are aware that the motherboard has to be removed to install the MC462 right? It will fit the IWill KK266/R just fine, just follow the instructions well.
The MC462 has a very nicely finished, almost mirror like bottom. I personally would not use a thermal pad on it. A good quality thermal grease such as Arctic Silver is the way to go. Just put some Saran Wrap around your finger and place just enough thermal grease on the core to smooth it on in a thin layer. The Saran Wrap on your finger will help in smoothing it evenly, and also eliminate getting oil from your skin mixed with the thermal grease.
EDIT: I just saw the post above mine letting you know that the mobo has to be removed.

The review that you read was correct about the washers not fitting the holes in the KK266, but on that board, and any other that has metal lined (grounded) mounting holes, you do not need the washers. I have installed an MC462 on the KK266/R without washers with no problems.