Type of 11 kV Post Insulator

Could it be, that the base of post insulator is analogues to our feet, on which we stand and cap is analogues to our head, where the conductor carrying your 11 kV goes?

are there any other type of post insulator than stack type?

sks

Look here

A cap & pin (what you call cap and base) insulator has a porcelain insulator body that screws onto a metal (or in the past, wooden) base "pin" that can be fastened onto a distribution pole or structure. Here's a photo you could have found on Wikipedia:

The station post insulator has metal caps on top & bottom, molded right into the porcelain, which allow the insulator to bolt to structures and cable/bus clamps. Here's a photo of them:

They are two different animals, for different purposes.