Not trying to be crude but most guys who have good private farms probably won't offer them up on the internet. That being said I can say that the best scouting tools are google earth and your truck. I use google earth to look at arial views for fencerows and larger farms. After that I just drive to them and ask. More times than not farmers are usually happy to let you hunt rabbits so getting some places really isn't too tough. I do the same thing with SGLs. It takes a few minuts to google the SGLs near you and then look at the arial photos.
Get out with some snow on the ground to scout for sign. This time of year is great for finding new places. If you find good cover you usually find bunnies. Google earth will definately help as Bearklr mentioned.