Did you get this done in the end? It is a right bitch to get to but it can be done with basic tools and a bit of dexterity and perseverance. If you have a deep reach socket to slip over it that may make things easier, otherwise break the top off it and use a standard socket though that's not going to help you getting the new one back in.

I dont think you can put it anywhere else as you're interested in the head coolant temp rather than anywhere else.

I've done a couple of these in the past, I even have a new one to fit but I suspect there is nothing wrong with the one that's fitted and the car is running warm/hot for another reason....

HTH.
Iain.