I was thinking, maybe you could incorporate the idea shown in this video http://www.metacafe......ack_security_system/
(Use the parts from an old CRT to throw sparks 1 inch long or longer.) into the mod. I don't know how hard it would be, but it's just a fairly random idea.
Edit: Maybe you could combine Squeemonkey's idea with mine. Use the glass/plexi as an isilator for it and have the sparks jumping around in the glass/plexi.
Edit again: I thought about the problem that the current wouldn't be able to just ride the air continually, so maybe you could find some high voltage capacitors and use them to store up some energy and then when enough voltage is built up it could jump maybe even farther than 1 inch. (Maybe 2 or 3)
This is just my idea, you don't have to use it and I don't know how hard it would be to incorporate it, I just think it would really pretty amazing.
By the way this mod is amazing as it is.