I'm looking to run a gas line from the main gas supply of my home, to a gas lantern about 140 ft away. The line will need to be buried in the ground and will have to pass underneath my driveway. I believe there is a flexible line with a trace wire that can be used. I want to do the majority of the work myself but will get experts to connect either end.
What are the regulations in terms of how deep the pipe must be buried and where can I buy the pipe since my local home improvement stores don't carry it.

I'll try to remember to grab my national gas code book tomarrow. I don't know where you can find the gas line, try calling some HVAC wholesale houses in your area.