For your purposes, blockchain.info
would probably provide you easier access to the data you are looking for.
As for the current distributions of bitcoin wealth, you're going to have a very difficult time accurately assessing this in any sort of meaningful way. Unlike bank accounts, tax returns, and other methods of identifying and correlating wealth distribution, bitcoin addresses and coin movement change constantly. Even amongst one person, bitcoins move from one address to another as new addresses are frequently generated by the users actions, and during the transaction process.
Another thing to consider is that, given the novelty of bitcoin and its mechanisms, comparing it to long-established, state-sponsored currencies is not comparing apples to apples.