There is a lot. I would just use after effects. There are a ton of free tuts.
Let us know when you get that far and I will give you some links to useful instructional material for your project.
I cant remember right now, but if TG2 can now save out an EXR and a tiff per frame at the same time make sure you do that.
Otherwise, if it can't, and you have good HDR software (I use photomatix pro with photoshop, not the plug in) than be sure to save .exr. But .tiff will be fine too if thats all you can work with.
It would be great if you have a particle plug in for AE like what "red giant" provides, as well as magic bullets looks. But if not don't worry. There is still a ton you can do.
The most important thing is to get as much of the action rendered out from TG2 as possible. The more details you have in the render to work with the better.
The blast wave you have that pushes the clouds out is great! I would add another cloud layer to it similar to the one you already have. Its a great detail