There are works by Patroclos Stavrou, and Lykavgis, both close associates of Makarios who kept notes and documentary evidence from their years with him.
The most insightful work I heard quoted was the one from his personal secretary which was withdrawn shortly after publication, in one of those great faux pas of Cypriot politics which wants the ethnarch to be beyond reproach.
One insightful instance from the above book is Makarios' expressed dislike for political defeat, saying he would not be willing to enter an election he was not sure to win. Brings to mind his contemporary Karamanlis who self exiled himself after an electoral defeat.
Oddly enough the comments by Rauf Denktash, although they may be scattered in other works, are another insight into the personality of Makarios. Deep down Denktash envied him and wanted to be like him. Read the comments and you will see what I mean. Thre is one case at UN sponsored talks, and Denktash states how during the hours long talks he excused himself to use the toilet and called out for sandwiches and drinks several times, as did the UN representative. For eight hours Makarios sat in his seat and did not move, did not eat or drink anything. Never underestimate the will power of a monk!