1972 LWB Tank Relocation

[muddpile]

I was thinking today that it would be nice to get the tank out of the cab and under the truck where it belongs. The only problem is I have no idea how to do that. The truck is a 1972 Long Box with rear leafs. I have a few questions about tank relocation:
1. Where can I get a gas tank to do this (what fits)?
2. How do I deal with the fuel lines and fuel gauge?
3. Where does the fuel filler door end up?
4. Is there a patch panel to fill in the old filler neck hole in the cab?
5. How much modification is there to the truck?

I figure its probably best to get the fire hazard out of the cab, and plus it takes up room for storage, stereo, etc.