if you are able to get the stats from that site into a useable database format in some weeks, then that will be pretty impressive. the people who have databases going back several years protect the info closely, and use it as an edge. so you would be ahead of many, many people
if you are able to construct the database.
also nice site you found.
http://www.basketball-reference.com/ is a similar site for nba; don't know one for nfl