Sure, you could float your colony in the atmosphere of Venus. But since you're basically creating a fully sealed, self contained system, why not just put it in space? Why bother with Venus at all?
Ok, it does have a few advantages over that. You get gravity for free (91% of Earth gravity). You get radiation shielding. You have access to some raw materials - but only what you can get from the upper atmosphere. You're not heading down to the surface to mine anything there! But all of those things are easily achieved in space. Rotate the colony to get gravity. Mine raw materials from asteroids or the moon. Use a physical barrier or a magnetic field to block radiation. And you have two huge advantages:
1. You don't have to worry about the outside of your colony frequently being exposed to clouds of sulfuric acid.
2. Venus is a really long way away! Having your colony much closer to Earth will make building it much cheaper and easier, and also make transportation a lot easier once it's built.