Actually, I'd never noticed that the symbol looked like a C - nice catch there. Still, it's almost certainly not part of the name, given that multiple in-game and in-universe references cite the company name as "Aperture". Plus, "Aperture" makes sense - an 'aperture' is a narrow hole or gap, as is a portal.
The android theory, though, is flatly bunk. Valve states in the developer commentary that Chell is human; the 'bionic jump boot implants' are simple shock absorbers, added to Chell's model to rationalize why she can survive any vertical fall, while characters elsewhere in the Half-Life universe can be wounded or killed by fall damage.
Still, even if she's only human, the game is still priceless. Especially once you find some of the better map packs out there, where you discover how vicious some mapmakers can be.
...What map packs and where can I get them?
It all depends. If it's generic map packs you want, Google is your friend. :p
However, I was (vaguely) referring to Portal: Prelude (
http://www.portalprelude.com/). It actually has a story and
voice acting, unlike most map packs (although, obviously, everything is non-canonical), and the puzzles are incredibly tough. Even if you've beaten Portal a few times, Prelude will stump you. Repeatedly. And then kill you. Painfully.