Cross-line course is also an option, especially if the width is 200' to 250'. I've also been involved with one on a lake 400'ish wide. Cross-line is extremely accurate if done properly and width isn't an issue. The issue is width and shorelines.
If I were to do individual anchors, I would prefer to do it in shallow water before the lake fills up if possible.
Another option is to layout boat guides and turns on a 2" schedule 40 pvc, then you only need 2 anchors per set instead of 3. (this way would also be easier if you could install before the lake fills up).
I have not installed one that needed to be sunk, so I've got nothing for you there. But Dr Jim Michaels can help you if you need one that needs to be narrowed for setting records and grabbing glory.