Wes! If that junker you run is the 12n-5.5a-3b, well,.. that's still your best choice. There are many "brands" available, so just get one that is warrantied, like an Interstate, and then get one of the "extention boxes" that are available from distributors like V-Twin or (I think) 45 Restoration, etc. This not only makes it convenient to get at the battery, but it allows airflow around it. Although vibration is bad, the heat of the oiltank reduces the batteries ability to accept voltage, and greatly shortens the battery's life. Therefore a "low-voltage" regulator for this application has been made by Cycle Electric to avoid the boiled battery syndrome.
These two products make the 'junker' battery quite serviceable.