Every Unix out there (other than the non-standard ones on pda's, etc) has a shell. Linux is no different. You can almost always type commands in the shell, even within a 'bubbly' interface.
Originally posted by Brian
No! Don't use Linux. Linux is very dissimilar to the Unix you will be using. Many Linux distros these days are guilty of XP'ing up linux, so you get a bubbly interface hiding all the power. If you want to experience a real Unix, download FreeBSD. It is surprisingly easy to learn, very powerful, and in many respects faster and more stable (i.e. less bloat) than linux.
Please don't flame me. I speak my opinion.