You can use the primers in this article (http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.0060204) Although there are 16 amplicons used in this study, you can just choose two primer pairs which have suitable properties and overlapping amplicons and amplify whole mitochondrial genome of Drosophila with these two amplicons. Then, Ion Torrent shotgun protocol can be applied to this pooled amplicons.