What did Rome look like before it became an imperial superpower? I know that Roman culture was from very early on influenced by the Greek city states in southern Italy, but there must be some truth to what Octavian said about "finding a city of bricks and leaving it a city of marble". I also know that most of the characteristic marble monuments was built during the era of the five "good emperors", a century later. Do we know of any specific ancient Latin building techniques/styles? I'm trying to imagine Rome as it was c. 350-400 BC, but I don't really have a clue as to how it might have looked!
There's actually some excellent reconstructions from the Museum of Roman Civilization in Rome for the period just around the beginning of Republican Rome. They're the ones who did the reconstruction for the larger Constantinian Rome dioramas you see in practically every movie or comic book on Rome.
Here's a link to the museum's website with some pictures of the diorama.
If you haven't been to Rome before, that museum is actually a good starting location because it puts a lot of Roman history into one museum organized by time period. The only problem is, the pieces will be facsimiles, replicas, and reconstructions. And I think the museum has some fascist origins, but whatever. =)
But yes, early Roman architecture was heavily influenced by the Greeks. Most of the Roman innovations in architecture, with regards to massive internal vaulted spaces come during the high imperial period.