Not sure if this will help, but it might give you some ideas. I moved from Scotland to Portugal supposedly to be sort of retired, but......
The 16 acres we bought has, or had, a lot of stone, literally 100% ground cover over a few acres, and less in others. Sorry I do not have a camera so cannot post pictures. Stone size is the same as you say, 2" to 2', but mainly less than the size of a loaf of bread. I built a vee shaped tpl mounted rake. Metric, but say 3 feet to a metre. 3 metres wide behind the tractor, 3 metres long and half a metre wide at the tail end. The walls are made up of angle iron say 3", top and bottom, and about 1 foot high, with sheet steel as the lining. Concrete reinforcement bars, say 1", behind the lining, use the angle to weld to, or drill through and weld (I now think box section on the bottom might have been better than angle) stick the re-bar (not sure if you call it that) about 4" down below the bottom angle/box section at about 1 foot spacing. That gives a narrow space when the vee shaped rake is pulled forward and it shifts all loose rock within 4 " of the surface. The rake is purposely wider than the tractor so that I can run alongside a row of stone and move it until the rake is travelling full of stone. I have very satisfactorily raked about 12 acres since I built it just before Xmas, and after windrowing pick up the stone with a box I made, also tpl mounted, solid back and sides and say 4" x 1/4", plate welded to a flat bottome and shallow slope as the leading edge (furthest from the tractor) with re-bar welded into the gap and against the back of the box. About 1 and 1/2 inch gap between the bars so that soil (sand in your case) and small stones fall through. I am in the process of using the stones picked up to fill a depression about 15 to 1800 square metres and up to 2 metres deep. I am short of half way, but have done more than enough to know that what I built does the job. Some stone is lost on each pass, and I have raked the worst areas three times, and might need to do some more - it is all to end up as arable and capable of being sut for hay, so I need to get rid of everything over about 2", but one pass gets rid of all the bigger stuf. Hope that helps. Old McDonald.