I intend to overhaul my suspension at some point and have been looking into polyurethane versus rubber bushings. There are pros and cons for each, assuming originality is not required. The polyurethane ones are easier to fit and potentially will last a long time, although there might be slight reduction in ride quality.
For the polyurethane I narrowed my options to one manufacturer, Strongflex, who offer two hardness levels on most bushings. Their red bushings are 80 ShA and the yellow ones are 90 ShA. They do a front suspension kit for £155 which contains a mixture, which they say equates to the equivalent OEM items. They don't seem to offer the upper arm bushings separately.
As for rubber, Febest seem to offer a comprehensive range, although they do require a press to fit.