When I ride here in Seattle and the temp's under 40, I wear SmartWool mountaineering socks--the warmest socks REI could show me, since my toes get really cold. Those seem to work, and you can always add the neoprene shoe covers over such socks if you need to--they will also help.

Re wicking layer: I also got this from the women cyclist/employees at REI---Ibex makes great jerseys from fine merino wool; to quote the REI gang precisely, "Wicks great; doesn't stink". They're not cheap but they're well worth it. Before you buy full price from the Ibex website, try Sierra Trading Post--they often have some kind of ibex top on sale at a great price.