I built my brother's S13 up from an empty chassis. What a friggin nightmare. It's been over a year, thousands of $$, and litterally, the car just started to come together today. It still needs paint and it's rolling on stock tiny alloys.

If you have infinite patience, infinite time, lots of money, a nice place to work, and are a whiz with a wrench, then build. If this is going to be your only car or don't meet all the requirements above, then don't even think about it.