ColumbiaMen's Snow Gun Pant, Waterproof, Insulated

I am a 34×32. When its really cold i would like to be able to wear long johns and jeans under these.Will a large work?

I'm 6'1" 215lbs with a 34" waist. What size would be ideal for me?

Small or Medium for a size 30x30?

I am a 32 x 29 in jean, dress pants... what size is recommended S or M?