Teaching high school TCS - existing programs
Many countries organize summer schools for their IOI teams 
(consisting of high school students aged roughly 16 IIRC). 
The one we have in Iran used to have the following courses: 


programming, 
data structure and algorithms, 
combinatorics, and 
graph theory. 




I think ACM's Computer Science Teachers Association has 
a K12 curriculum on its Curriculum Resources page
though it is probably way too light for talented teenagers. 



I think programming must definitely be part of the curriculum. 
Python should be a good first language to learn.

You might want to also cover some accessible topics with applications 
(the joy of building something cool can have a big effect on their interest).
I think Andrew Ng's ML course on Coursera 
should be accessible for talented students
(specially for those in countries like yours where 
there is a more serious K12 math curriculum ).

A nonstandard topic that you might want to consider is combinational game theory,
it might be not very interesting with 16 years old (I don't have experience for it) but 
it works quite well for a bit younger students in my experience.

I personally think the central and connecting theme should be around algorithms,
I think it would work better than automata theory as the central theme and 
arguably the algorithmic perspective (not Turing machines, automata, etc.) 
is the essence of computer science.