I’m doing the same thing at the moment. The bushes wear and will likely need replacing too. Oil seals, genuine NOK are recommended but if the dust seals need replacing then cheap ones should do. Bushes, Yamaha or could try aftermarket. Got mine from K Tech. Also have K Tech linear springs to go in. Mine are fully stripped down and need to find a few hours to get them back together.
Oil- K Tech recommended a 10w Motul Factory. Of course people change to their preference so not sure if a best oil can be determined. 1 litre is enough for both legs. Something like 0.44Ml per leg but needs to be measured via air gap rather than actual amount.