Congratulations on the new purchase. If you are going to shoot 500-1,000 yards get a good scope. You need to have a broad range variable, but it has to be clear, good parallax adjustment and keep the same POI from shot to shot. On some days you will need to crank it was down to get rid of mirage and on others want full power to see the targets more clearly at those ranges.
I would not use less than a 8X32 for that kind of shooting. Before you plunk down $500.00 on a new scope, go to a place like www.AccurateShooter.com and search for used scopes for sale.
The scopes on my factory rifles all cost more than the rifles. For benchrest shooting, on my custom rifles, from 100 yards to 1,000 all my scopes are Nightforce, Sightron or Marsh.