The rubber bushings in your suspension and steering provide compliance - the ability to absorb shocks transmitted from the road. Going to polyurethane or similar materials eliminates the compliance benefit and allows road shocks to be carried directly into the body and steering wheel. That also allows a lot more noise into the cabin. Poly is great for a track car, not so much for a driver street car. And... yes your car has a steering rack. As for replacement shocks, KYB makes a great shock with stock-like qualities.
Look up your suspension bushing part numbers on the online catalog and see if any are still available from your Nissan dealer. Then got to Rockauto and try to fill in the gaps. It is difficult to impossible to get OE rubber bushings for most steering racks - pretty much unicorns, so it is a good chance poly will be your only option there. If you come across any Beck-Arnley rubber bushings, grab them as they are an excellent product.