This isn't exactly easy. The site will need a heavy backend that talks to a whole array of old legacy databases to pull the data out, meaning you will probably

This isn't exactly easy. The site will need a heavy backend that talks to a whole array of old legacy databases to pull the data out, meaning you will probably need to have people proficient in cobol, db2 and all sorts of other greybeard stuff. You'll need to be able to scale well with large amounts of data, and you need backups and redundancy of this. You will also have to be able to play the political game, expect pressure, and expect specifications to change often due to politics. I think I could do it in a weekend.