I remember looking at a star wars site that applied real world science to a lot of the aspects of the movies (i.e. the fall out from the second death star destruction causing a holocaust on endor) that could help you with finding a good looking explosion it might just help in general too. I have to search around and try to find it again though. Ill try to get post it up ASAP (unless another member knows what Im talking about)

Edit:...found it here

Here's something that talks about the yavin explosion that you mentioned

Didnt remember it was from TF.N so I dont know how much it means to members around here.