painting control arms

Hi, I am refurbing my control arms on my 68 Valiant and i have blasted them and primered the ucas and moving to the lcas next. I'm looking for the best paint to use to prevent it from rusting. Thanks.

Side note. I noticed after having a very tough time removing the ball joint nut on the ucas and having a very tough time, that the threads are almost non existent. Will that be a problem when rebuilding them?

Thanks.
I'm redoing my suspension right now too and the upper ball joints don't have really deep threads they are shallow my moog replacements are a little more course but not much!

20180619_184546.jpg