Phil, I will help as much as I can mate.
Any quill can be made into floats, and that's both ways up.
To clean a quill use scissors to remove as much feather as possible then use wet and dry to finish off, rub as little as possible but remove the gloss as this will help varnish/paint to adhere.
To straighten the quill use very gentle heat, I use the handle of an old type smooth school stainless steel knife.which I have warmed over a flame. Pull the quill over the handle with your thumb holding it fairly firmly and pull across a few times.
Once you have your prepared quills decide for what use you want to use them for. Big end up for river type stick floats so you will have to add a heavier wood stem or thin end up to use as a waggler. The smallest thinnest quills I use for crucian type fishing gradually getting bigger one to carry more weight.. If you want a quill to take a certain weight set it up and and test it and cut tiny bits off until its carrying just a little less weight to take account for any paint you apply, then dry thoroughly before painting.
To paint use a thinned white undercoat/basecoat let it dry then apply colour of choice.