[RussMurco]

I've built a couple of 2nd gen and one 3rd gen Camaro and am preparing to build another 2nd gen Firebird but am hesitant on bushing choices.
On these cars I have tried several different poly bushings from a few manufacturers and ended-up going back to rubber each time. The harshness from the impacts was jarring and on the 3rd gen car I even had a suspension company's tech make sure they were installed and lubed properly to eliminate installation issues, they were spot-on. I have tried products from PST (graphite-lubed poly), Energy Suspension, and 2 other brands that escape me at the moment and each of them was a disappointment.
The car I am planning is going to have significantly enhanced handling but I have no expectation of chasing down the Pozzis, Steilows, Tuckers, or Finches on the track. This car will still be used on the street 99.5% of the time and I draw a fairly distinct line between race cars and street cars and what I will tolerate in each. I know a Pro-Touring car is, by definition, a car that blurs the lines but until we start hanging lights and plates from tube-frame cars I still consider them street cars.
I was looking at the late-model suspension bushings on these chassis kits many of you use, particularly the C6 stuff, and noticed that the later stuff used much smaller bushings that I am assuming are rubber. The 2nd & 3rd gen bushings were huge in comparison, do they need to be poly (or worse, solid) to achieve stability under high cornering load? My budget dictates I stay with a factory subframe and I've considered the Del-Alum bushings hoping that they would give slightly better articulation and with that a better ride from less binding but I see nothing that would minimize impact harshness. Am I looking at that from the wrong perspective? Is there a poly brand that wouldn't transmit so much harshness, or a higher-durometer rubber bushing available as an OEM-size replacement?