Extreme cold weather... what oil?

[shuttermutt]

Where I live, it gets kinda cold...

Average High in Jan: 19°F
Average Low in Jan: 0°F

Average High in July: 76°F
Average Low in July: 55°F

Record Low: -41°F (set in Feb 1955)
Record High: 96°F (set in May 1977)

Last winter we routinely saw sub-zero temperatues all winter and we had snow drifts taller than some buildings. At one point, the snow completely covered my wife's Ford F-150 in one night and my BMW had nearly 3 feet of snow on top.

Needless to say, I'll be investing in a block heater and battery blanket in the near future for my truck. However, this will be my first winter of this extreme with a good ol' SBC and I'm wondering if anyone has engine oil recommendations. Right now I'm running standard (not synthetic) Quaker State 10W30.

Oh, and I've got an oil pressure issue when the engine is warm. Basically, it doesn't have any and she knocks a little bit down low (also known as a Very Bad Thing). Thoughts anyone?