If you're getting a baby, go with a small tub. The 41qt would freak a tiny baby out. Now, a snake that is around 1000g would usually be fine in a 41qt.

Babies under 500g go in 6qts
juvies 500-1000g go in 15qts
subadults/adult males go in 32qts
adult females go in 41qts

Works well and no one fasts or is stressed.

And use the flexwatt. Whoever shipped the flexwatt to you didn't know how to pack it. www.reptilebasics.com ships it to you rolled up so it won't get damaged and it's padded well in the box. I've never received damaged flexwatt and I've bought too much of it really... Flexwatt is $3.40 a foot for 11" and ultratherm pads are quite a bit higher than that. I'll go with the flexwatt any day.

But you do need a good digital thermostat. If your room temp goes too low, cover the tub with a blanket, and don't put too many holes in the tub.