I am also looking to lighten the steering on my Roadster S2 at parking speeds. Simon H advised that rather than replace the bearings they should be stripped, washed out and greased, assisted by new hard chrome king pins and phosphor bronze bushes.
I'm not entirely sure what bushes or pins I have. My file doesn't have any receipts for replacement, but being around 45k miles, and an advisory or king pin play several years ago on an mot, which disappeared in subsequent mot's, I assume they have been replaced. I would expect it originally had devol bushes. Unlike your s2, I don't have any bearings at all.
