If you keep the rake angled in, you won't get rocks into the lawn in the first place. You could, with precise adjustment of the gauge wheels, rake some rocks off the lawn as long as the lawn is pretty level, otherwise the rake will try to level the lawn.
The rake w/gauge wheels is one of the most useful attachments. I've had one landpride rake last through four tractors.
You will want to get one that's not much wider than your wheel track otherwise it'll be too hard for your tractor to pull. You can get more done with pulling a smaller one fast than having one too big dragging the tractor sideways when you angle it or stalling the tractor whenyou pull it straight.
The biggest advantage of the proper size rake is you'll be off the tractor all the time readjusting a rake that's too big, where you can just drop and go with the right size one.
Check your manual, it'll tell you the max rake size recommended, I wouldn't exceed that by more than 6"