[sisforsurfing]

Someone has to say it so I'm going to get it out of the way...
Modifying that car will give you a VERY poor hp/$$ ratio. And it's also been stating that you have a very reliable car with good gas mileage and the best resale value in the world. In my opinion you'd be better off saving those good features by not modding it, saving up three or four thousand bucks (since you've said your Civic is paid off), and start building something else... DSM, 240SX, older Honda w/a swap, etc, even a fox body Mustang.

Now that that's out of the way, if you're set on modifying this car, do brakes and suspension. It's never going to go fast in a straight line, but with decent brakes, suspension, and lots of driving experience you'll be able to have lots of fun with autocross. Good luck and have fun.