Your question asks for several alternative forms. From the start I'd say that the versions with suficientemente are all correct, whether they use lo and/or como:
- ¿Es lo suficientemente inteligente como para trabajar en Google?
- ¿Es suficientemente inteligente como para trabajar en Google?
- ¿Es lo suficientemente inteligente para trabajar en Google?
- ¿Es suficientemente inteligente para trabajar en Google?
In the case of bastante followed by an adjective, on the contrary, not using como sounds incorrect to me, but I haven't been able to find a proper source. (Note that bastante, when it functions as an adjective, does not need como.) The same goes for using lo. So I would say:
¿Es lo bastante inteligente como para trabajar en Google?
With bastante there's a small problem: bastante sometimes connotes an opposition in the same way as muy/mucho or demasiado, because its meaning can vary from just enough to quite a lot.
Es bastante mayor como para ir sola al colegio.
"She's old enough to go to school by herself."
Es bastante mayor como para tener que llevarla al colegio.
"She's rather old for (someone) having to take her to school."
This doesn't happen if you use lo, since lo bastante always means "the amount which is enough" (the positive connotation of bastante); it cannot be used to mean "rather, a bit too much, enough and more".
Using bastante + adjective, without lo, in a question, sounds distinctively off to me, but again, I don't have a source for that, just my experience (as a native speaker among other native speakers).