Hey Dark......5W-20 is OK...5W-30 OK..some change viscosity with inclimate weather......That's all up to you...
I am not a big fan of Exxon/Mobile, but...
http://www.mobil1.com/index.jsp
Any Exxon or Mobile gas station should have it...
Oh and my personal favorite..Chevron carries it as well...
http://www.chevron.com/prodserv/nafl...motoroils.shtm
~Have fun......Jenn~