Thanks for the replies.
It certainly seems like an interesting and complicated area in regards to thunderstorms. I scrolled through the Grafton and Brisbane radar loop archieves last night. Some patterns certainly emerged. From what I observed from October through to December a lot of the storms that develop in Dorrigo tend to make their way up through Grafton, Maclean and Evans Head, whereas the storms that develop near Jackadgery tend to end up around Casino, Lismore, Kyogle and then make there way up to SE Queensland. From January through to March they tend to get really fair dinkum and start up to the southwest of Dorrigo and head all the way up to the NE corner of NSW where they turn into real monsters.
Admittedly, I only went through the last two summers radar loops but still got enough info to get a rough idea. Seems like Grafton would be an ideal spot to intercept some of the storms. Its a realistic drive from Coffs but I think the likes of Kyogle and Murwillumbah could be a bit far.
On a side note, I noticed Coffs almost completely missed out on the action from January onwards last summer. But I will take your word for it David and consider this a mere aberration to the norm.