Proturing or roadrace rear suspension

Which gets to what are you going to really use the car for? Any sort of motorsports competition is going to have rules. So you'll find people actually wheel to wheel racing, or even hillclimbs or FIA rally limited as much by tire rules as any thing else. But those who are just enjoying track time are generally pretty free to do what ever they want. And there's some places to play in between those two worlds.

If you like building things, then do whatever you want. If you're thinking about competing in anything, check the rules, go and observe what the other players are doing. Then spend the time on tuning and seat time. In competition, the biggest variable is the tires. Change them, and plan on making some adjustments to everything else.

I agree that leafs and t-bars will do fine for most purposes. For very fast, like 120+ adding a panhard can be worth the trouble. Daves got one on the Zebra Dart, one of the 70 T/A teams use one, and at least one of those cars is using one the last time I had a peek underneath.