I've done a tone of research on panoramas, and they say that ideally you want about 30% overlap between images. They make expensive tripod bases that have specific degrees of rotation so you can set it up and quickly rotate the camera until the base 'clicks' into place. There are tons of things you can buy for better panos. I've personally found so far that scenes like this can be done using a good tripod and leveling base. Keeping it's 100% horizontal and level through out the rotation is critical for good stitching, but mine aren't exactly 30% overlap.