I've got some interesting Ideas but I've already (subject to change) got the look I am going for......For glow effects have a search in the modelling and painting sub form, page 3 the is a guy called millest with a project log called "house hermetika" imperial knights, he did a great glow effect using ink over silver to get a purple glowing effect. There are several old threads lurking around in the hobby section if I recall.
Most people do plasma in the blue and white. You can do a base coat of white, wash with a dark blue at the base of the coils and work up to a light blue at the outer edges or paint the coils dark blue and build up layers of lighter blue up to pure white at the outer coils.
Air brushing obviously gets the best effect, Miniac, warhammer TV, Darren Latham miniature painting, sword n Steele, midwinter minis, titan miniatures, all on YouTube do great tutorials on plasma glow effect with and without airbrushing. Hope that is of some service to you old boy, and as always loving that work of yours!