I don't know about the EGR valve, someone else will have to chime in on that.
Steve Wong chips:
911Chips.com - Porsche Performance Chip Tuning. Under the FAQ he says they should still pass smog, and he is based in LA. There's info about the fuel map used as well. The chip I have appears to be for 93 octane gas, we only have 91 around here. Not sure if that matters. Unfortunately I don't have the original chip.