Wake up nick , of course I used the old electric tank, your questions are so relavent.
They require alot of Btu mine is 117000 next size up is 180000 btu, that takes alot of gas to be sure when you need the full btu its there. I use
1/2" but over 10ft I think its 3/4" or so. For the 180000 btu and a long gas supply it has to be calculated. Mine is in the basement.