With Total Tools, the cylinders must be collected in person and you could be asked why you are making the purchase. The cylinder gas pressure from Total Tools is 200Bar and will need to be bled down to ~150 Bar for safe use with a Max Dog regulator,
Small, convenient take home 220-liter nitrogen cylinders are available from iKegger. With a suitable flow regulator, this will provide 15 min of gas flow, adequate for a peaceful death.