Terry, Mike had the good info on the GM columns that most folks have used in the past. Unfortunately many of these have been well picked over and the better ones gone. Then there are the other bug-a-boos, the missing key, the clunky plastic cover, wiring and a connector that's cut, broken or missing. Then you need a steering wheel adapter and nice wheel. All this means is you start approaching the price of a nice after market IDIDIT or Flaming River, especially if that column needs rebuild. Both have column shift versions and (reasonably) easy to connect linkage

Gas tanks - the late '50s - early '60s Chevies and GMs had an about 16 gallon tank behind the seat version. I used one for an aux tank years back, bed mounted in my '76 and '79 F350's. It wasn't internally baffled so even mounted in the bed, you could hear gas slosh plus was pretty wide. With that said, TANK'S Inc have a nice selection of good after market tanks along with sending units and pickups that are easily available.

It's really a shame that so many of the parts that we used in the '60-'80s are gone or are in such bad shape with the new and 'improved' items now sitting in salvage yards, and in many cases, not easily adaptable. Luckily the after market makes some replacements, but you sure do pay their price and that's keeping many, and especially younger folks away from street/hot rods

We need pictures of your build, too