I've not used either, but White Knight Squirts seems pretty popular for war gaming miniatures: http://www.wargamerau.com/forum/lofi...php/t9737.html

Plasti-kote could be ok too. The suggestion is to sit the can in some warm water first to get a finer spray, and you may need to overcoat with clear first if you're adding more paint or a wash.
http://www.dakkadakka.com/dakkaforum...st/265523.page