[ApacheResistance]

You should be fine with any of those gaskets. I normally use fel- pro gaskets.

As long as the gasket covers the metal on the thermostat housing that makes direct contact with the block you'll be fine

Teflon Tape is a lubricant - not a sealant. It just makes it so you can tighten it down more. Same concept with pipe dope. Buy an actual sealant. You can wrap the threads in Teflon (wrap it clockwise on the threads if you're facing the pipe) and then put sealant over that for double protection.