When it comes to snow, boxes (weather it be a box blade, front box, or your loader bucket), those are really designed for moving snow longer distances. Great for parking lots, parking areas, etc. But suck at long and skinny "roads"
There is a reason road crews use angle plows, and contractors doing parking lots use push boxes.
For 3000' of driveway, you want something that angles. One pass down the drive/road.....widen the approach while down there, one pass back up and you are done.
If I were you, I would rule out a front loader mount angle blade. Do you have front hydraulics (3rd function or diverter)......if not, consider adding some. But if not, some 1/4" hoses running to a rear remote......$100
For the plow, There is a plethora of 7.5, 8, and 8.5' plows all over craigslist in my area. Dont know about yours. But with $500, I could probably show you at least a dozen within an hour drive of me. Then its a simple matter of attaching to your loader. Assume you have a SSQA???? What other attachments do you have? I mounted my plow on my forklift frame after removing the forks. But a blank SSQA plate and weld on some tabs for the plow.....~$120.
Again, dont know your setup. Or your fab abilities, or what you currently have. But I spend $350 on a front 7.5' plow. Already had hydraulics for the grapple, and used my fork frame and some scraps of metal to make it accept the plow. So I only have $350 invested in a front plow. And you arent gonna touch a rear blade heavy enough for your tractor anywhere close to that, let alone one with hydraulic angle.