If you're a Nissan kid, get a 240SX - RWD (which is a big plus), 50/50 weight distribution, semi-cheap used, and also has a sizeable aftermarket for suspension; not so much on the NA motor side. Not much you need to do to a stock KA24DE to make it fun though. It doesn't rev as easily as an SR20DE or have quite the power of a DET, but it is still a very good motor - torque + RWD = lots of fun.

Rear strut bar does help a little, but not enough to make a big difference. The ITR or Comptech sway out back works very well with the stock front bar, which is why the same one is used on the ITR. Sunroof = useless in a car for auto-x.