I'm looking for a survey of the political and religious institutions of the Roman Republic. I'm going into it with a course on the republic under my belt, with a couple lectures devoted to these institutions, so I'm familiar with the basics. I've also read the first five books of Livy and Machiavelli's Discourses. I'm interested in a little history (in the sense of events or sequentialism), but mostly understanding the structure of republican political and religious institutions/cults, the personalities that inhabited them.
A great place to start would be our recommended books list on Ancient Rome, found here.
This is not meant to discourage further discussion/suggestions in this thread.
I've studied Roman magistrates (with imperium) in the Middle Republic, which is closely related to the subject you're inquiring after. I can highly recommend the following chapters and books, though I must admit the publication dates reveal when I studied this topic. Other good publications may have been made since.
This chapter gives a good overview of the Roman institutions and magistrates, including developments over time.
Another chapter in the same volume, giving an overview of Roman religion and it's place in society. Not a lot of depth, but useful as a quick start or a refresher.
Quite literally the book on Roman governance. Also check for other works by Lintott. It's pure gold if you're into Roman politics.
This book examines the role of the Senate and of magistrates in Roman "foreign policy" decision making by looking at various elections, wars, and treaties. It is focused on the Roman side of things; Eckstein's later works focus more on the international relations context.
If you can read German, the following is quite similar, but for the later Republic:
If I understand you properly you're really interested in magistrates and other collegiate positions. The major magistracies and various elements of the "constitution" have been addressed--I deal a lot with minor magistracies, people like the apparitores who accompanied senatorial magistrates. For those kinds of guys (I have no idea whether you actually give two shits about them) take a look at Purcell, "The apparitores: a Study in Social Mobility," in PBSR 51, 1983 (Papers of the British School in Rome). There's also Badian's magnificent piece "The scribae of the Roman Republic," in Klio 71, 1989, which is the most thorough study of any minor magistracy I've ever encountered