Good suspension starts with the proper spring rates - torsion bars and leaf springs. At this point, reinforcing the chassis is almost as important. What good is the proper spring rate if the chassis flexes every time the suspension compresses.
After that, sway bars add roll resistance. Some cars like the 108 wheelbase cars can get away with no rear bar. Here, quality shocks are also super important. The Bilsteins out there now are proper length, and pretty much a no brainer for the general build.
Geometry is also important. Stock upper arms with offset bushings are perfectly fine. Any other purchase is purely because you want to - not necessary. Proper alignment is something that is screwed up on a daily basis. That includes setting not only the regular toe, caster and camber, but leveling the ride height and squaring the chassis critical points. How many have done an alignmnet where the thrust angle is zero and front offset is zero? It take time, patients and a good machine and you can have a car that tracks well and drives great.
Last on the list is wheels and tires. If you think you are going to build a modern performance vehicle with 14s and 15s, forget it. The reality is that the cheapest car on the planet, will destroy you in any track event, pretty sad. My philosphy on building cars, is that if the car isn't usefull, reliable and better in every way than your daily driver cars, why bother? The only area where these cars will never excel at is being weather tight.
