Hi Peter, good questions.
Think Gavmiester wrote a thread about 2-3 years ago about tools required at different levels.
The fret ruler and rocker seem pretty cheap and well priced, if you think you will build more than one kit (this is very likely !) it will be worth the purchase.
The most basic tools you will need are phillips screwdriver set, drill and drill bits, sandpaper and sanding block.
You can make a straight edge sanding beam out of a long spirit level and glue sandpaper to that for levelling frets, there is sticky sandpaper available.
Then there are other power tools to make the job easier orbital sanders are handy.
To cut the headstock shape a coping saw and files (you can get away with sandpaper) are required. An electric jigsaw will make it easier.
What kit have you got in mind ? most first kit builders manage fine with a set neck kit.
NOTE Peter this is all the tools from memory, I have probably missed some