Forget about the academics (Lisp? SICP?.) You want to make a web app RIGHT NOW and make some cash. If you are good with PHP then look no further. Start working on your apps ASAP and update your PHP skills as you go. Take a look at the Zend Framework and CodeIgniter for some good frameworks.

If you must learn a different language then learn them on the side (hobby) while you are making your bread with the rest of your time using skills you already have.