any ideas on what i should clean the tank out with???
You mentioned above that you are getting a service manual for the bike. Is this different from the one you downloaded here? Is it a Harley manual?
IMHO I would leave the ignition stock. It will be a truer classic bike with the original ignition system. Same thing with the carburetor.
On the fuel tank, once you drain out the gas (hopefully you did what Glider suggested and drained it in something you can inspect), take the tank off the bike. Here is what I would do. Others may disagree.
I would take off any exit valve and screen assembly that may exist and wash them thoroughly in mineral spirits. I would then put the garden hose in the tank, plug the exit and completely fill the tank with water to drive out ALL the gasoline and reduce the danger of working on the gas tank. Once I had flooded the tank completely (letting the water overflow a bunch), I would drain out all the water and get my eye ball and a penlight in the tank to see how it looks.
If it is COMPLETELY rusted up in there with rust flaking off the tank walls, I would take the tank to a shop and let them hydro-blast or slurry-wash the inside of the tank to remove the loose stuff. Call around to the Indies or race shops in your area for references - tell them what you need done. Then get suggestions on if and what to coat the inside of the tank with.
If it looks good in the tank (no loose looking rust patches on the tank wall), then dump about a quart of alcohol in the tank and swirl it around trying to get the entire inside surfaces of the tank exposed to the alcohol. Dump that out and repeat several times (say a gallons worth). Stick a hair drier blowing in the tank with NO heat and let the inside of the tank blow dry completely.
While that is happening, replace all the fuel hose leading to the carburetor. If you have some metal line too, take them off the bike and chase them with choke cleaner spray. Disassemble the carb again and clean that out making sure you spray out all the orifices with carb cleaner. Reassemble everything.
Check the inside of the tank again to make sure it is completely dry. Mount any screen and valve system and secure the tank to the bike. Hook up the hose from the tank to the carburetor. When you fill the tank with gas this time, run it through a filter (like a doubled pantie hose foot section) to make sure no debris is introduced. Fire up the bike and readjust the carb. Set the points and timing.
Run around and have fun!!
TQ