If you are mainly concerned with cold weather statup flow, I would go with the previously suggested Amsoil SSO 0W-30, or Red Line 0W-30, or 5W-30 (what I use in the winter, since it has NO added pour point depressants, nor viscosity index improvers).
The Amsoil HDD 5W-30 Series 3000 is also a VERY good, STOUT, high TBN oil, which is highly resistant to washdown/fuel dilution which is more common in cold winter temps/short trips.
But it IS thicker than ALL of the above at 40 and 100 degree centigrade engine temps.