Seeking a Top 1000 site list for study

As you might know, I'm not only tutoring for the Web Analytics Award of Achievement at UBC and working on WASP, I'm also very interested in research & education. As part of my involvement with Laval University eBusiness MBA program (Quebec city, in French), I would like to conduct a research on something that have never been done before.

What is the true value of web analytics?

The goal of the study is to find out and quantify how much of an impact web analytics might have on the bottom line, and predict expected ROI. Some possible questions:

• Are top performers using more sophisticated web analytics tools?
• Are companies with a more mature analytical culture more profitable?
• Are they achieving significantly higher online conversion rates?

Seeking Top 1,000 online sites

I need your help!

I'm looking for a "Top 1000" list of some kind (top online retail sites, top UK sites, etc.) ranked by traffic, or better, by benefits or conversion rates, with available public information. If I can get more then 1000 sites it would be even better since I want to create a predictive model out of this data.

I'm thinking of Compete, Comscore,  maybe Bill Gassman from Gartner or John Lovett from Forrester/JupiterResearch have such a list? Of course... I simply can't afford to pay for that data... But I would be delighted to work and share my results with whoever can get me this list! :)