I did a search but nothing came up. I am looking at the TA47-2 and TA47-6. They have the carry handle mount. I plan on using it on a 16" flattop. They would require a flattop adaptor.

Should I buy the carry handle version or buy the special ring ACOG? I need it to be high enough to clear the front sight and possibly inline for my PVS-14.

How is the eye relief on the 2x?

Does trijicon made the circle dot reticle anymore?  

I am undecided on the red vs. amber reticle.

You can get what you want by mounting it on a flat top, but if you are looking to use NV, the Trijicon makes a flat top mount for the compact ACOG. the model number is TA60.

you will probably have to mount the NV in front of the ACOG since the ACOG have a eye relief you will have to deal with.

I like red better, it is a better color then amber, it will stand out better under different light conditions.

Trijicon makes a dunut reticle, the circle dot was a prototype reticle released some older TA01 as a test.  I have only seen one on a Surefire instructor's weapon.

Is the M16 base version more rugged then the special ring version ??

no, both are rugged, some people like to mount the optic on different, all you need is different special ring base to do that, and of course time to rezero the guns.