Nattys Wax from Poorboy and Pinnacle Signature series waxes have worked for me on Silver.
As far as synthetics go, UPP, EX and AIO work very well on Silver. I like to use a synthetic first and then top it off with one of the waxes.
WarrenA's advice is great. Many folks have experimented with different combinations and have posted pictures of the results. Do some searching. Good luck!