You can start by reading the results from this thread...
http://www.ft86club.com/forums/showthread.php?t=109320
I do think reaching 300whp will be difficult while remaining 100% smog legal.
I have the JRSC CARB legal setup and made about 230ish ... to make more than that you will need to remove cats, change exhaust components, probably run E85 and use bigger injectors and fuel pump.
** Caution, do not discuss ways of illegally circumventing smog requirements on this forum. This could subject you to ban or suspension. **