The internet revolution can’t get to the RE fast enough. I hope, one day, all of these info will be public and you can easily do a search using your favorite search engine to get all the data you want and construct your own analysis using a spreadsheet app.
There’s really no statistic that will be able to tell you where the bottom is. You won’t even know where the bottom is until you past it. People who like to call bottom will call bottom all the way down. Just like people who like to call top called top all the way up. I’d say, don’t worry about the bottom and just buy a house when it make sense relative to income and rent. The rest will fall into place.