Considering a pair of Flat Head 1001's. Anyone know what size I would take if I wear 31 in Sugar Canes and Iron Heart? Having a tough time deciding between a 33 or a 32 in the Flat Head. Looking for a fit without much (if any) sag. Also, will the 1001's continue to shrink after the first warm soak? I've read that FH denim stretches a little, but not much. Mostly wondering whether the first soak gets all the shrink out. Thx.