I really don't think there is such a thing as a mechanic in a can. At least one that works.
The biggest part of the head gasket replacement on these engines is the engine removal. But once the engine is out, you will be amazed at how simple this engine really is. Just follow the procedures to the letter, and it will go back together and have no issues.
I have no experience with these inserts, but I do know they are similar to many other types of insetrs that are commonly used in the trade, such as Heli-Coils. You just have to make sure the hole is properly drilled, which this jig apparently covers. It's really a straight forward operation.