I use 5w-30 winter and 10w-30 summer, full synthetic. Running conventenal, semi-synthetic or full synthetic is your choice. I run full synthetic because of the fuel savings, lower operating temps., ease of start-up (especially in the winter).
I use Schaffer's oil when I can get it. If I can't get to the local supplier, I usually use Mobil 1. You may want to consider using a full synthetic at least in the winter.