Good links from HillRider & Jeff Wills there

Specifically for your question about hidden cable STI's, you only have 5 options here, 3 mechanical & 2 electric. Tiagra (4600) isn't hidden for the shift cable.

Mechanical
5700 (double) /5703 (triple) - 105
6700 (double) /6703 (triple) -Ultegra
7900 - Dura Ace

Electric (Di2)
6770 Ultegra
7970 Dura Ace