Most “regular” digital balancers are pretty correct. That road force one is just a bunch of bull. My vettes tires are balanced on a regular digital one and they don’t shake at all, even at 150mph+
Unless by “old shitty balancer” you mean the old type where they lie the tire on its side and weigh down the light side.
Oh and if your looking at spending money look at getting a c6. The base c6 has a ls2 at 400 hp. The used c5 zo6 and c6 models are about the same prices already. (~25-30)