Source Four Drama

I am currently in the process of trying to find the simplest and cheapest way to convert two ETC Source Four lights into makeshift follow spots that I can use to follow just actor's faces in most scenes.  Luckily, with the help of @TechieTalk and their website, I was able to figure out some of the equipment I will need in order to get this final product:

I will definitely need the large lens tube in the front, the follow spot handles, and the drop in iris.  Ideally, I would love to get the yolk on an axis so that it can move and function like a real follow spot, but unfortunately, that particular part is over $600.  All I need to do now is convince work that this is some equipment we ABSOLUTELY need.  Wish me luck!