Anyone can whip up a registration and info-collection website. Well, anyone except these guys. Even under the tremendous user load, it's doable.
However, it is the MEAT that will put the date out five years, minimum.
I would abandon the “one session” model. You should sign up and be told you’ll get an e-mail when your information has been gathered from the various databases. An IRS tax return isn’t processed in 5 seconds either when you submit your tax returns online. It’s probably an unrealistic goal to do this in real time, because of all the potential links in the chain coalescing that data that could break.