MIZIKETSK

I was just curious to know if there were any serious mods done the the car or motor to drop in. I was looking to get a B18a, but peeps were saying just get a B20 because there's more torque. And will it pass smog in Cali? I want to be able to pass smog. And what's the difference between all the B20's ? Please educate me a bit on these B20's , B20z...... I would like to Go Gsr or Usdm B16 but don't really feel like spending another "G" for the extra power. Do you think $2900 out the door is a good price for B18 or B16 droppped? And how much do B20's go for? Any help will be much appreciated. Sorry so long.