Bachman Pawn in Dallas usually has good prices. I couldn't find a website for them, but they do business on GunsAmerica and Auction Arms and the like.
I think that you'll find it difficult to find a good deal on those rifles right now. They seem to be popular. Add in the cost of shipping and FFL transfer fees and your local shop can probably come close.
Have you asked your local dealer if he is willing to negotiate? Have you picked out all the supplies that you will need, such as extra magazines, ammo, case, and cleaning gear, along with the rifle? You might try going to the counter in your local store with all of the supplies you want, along with the rifle, then have the sales person calculate the total pre-tax bill then offer 10% to 15% lower than the total for the whole package.