I am not too sure of your reasons of setting linear lighting aside… with a globe of instanced linier lights you would pretty well get the effect I believe you are going for, and to a low expense (I am personally going to go for that for the lighting within the Stone… Even though I am going to light it a little different than the book would have fancied me to).
Linear lights where acutally my first choice. The concept was to create a bank of them around the circumference of the plasma tube and stretching them along its length. Sadly after spending a few hours on them I was getting so much noise from the lights even with them spinning around the plasma tube that there was no hoping in using them.
So from there I moved to expensive area lights which worked wonderfully but with long renders on my setup scene which is 1/8 final resolution. So I took a couple hour break during which for some stupid reason the concept of using point lights jumped into my head (distance and spot lights just did not look right). With only a few minutes worth of work I got decent results with the point lights for the plasma tube.
The most impoartnat thing to note with them is I controlled who gets light from them and they are actually only adding just alittle light to provide a nice GI (sans-shadows) look.