Both a custom and a nice higher end factory rifle are good options. IMO you should go with a semi custom or nicer factory rifle such as a Seekins PH3, Springfield Waypoint 2020, Weatherby 307 Alpine CT, or a Weatherby Mark V Backcountry 2.0. There are many in your price range that are outstanding rifles. I’d also consider a Browning XBolt 2 in one of its flavors.
Do you want an accurate hunting rifle you can shoot long range with or a long range rifle you can hunt with? I’d recommend a slightly heavier rifle the more long distance shooting you want to do. I have a 300 PRC that weighs about 9.5 lbs with scope, rings, etc. It is wonderful to shoot, but it is not the lightest rifle to carry for miles and miles. I have a 7 lb 6.5 PRC for that, but it’s not as easy to shoot steel at 800 yds with.
For a long range rifle to shoot bug-hole groups and consistently, ring steel out past 600, I would absolutely go fiberglass/carbon fiber stock with a bedding block. Carbon fiber wrapped gets you bull barrel rigidity without all the weight. I don’t believe they last any longer or shorter than all steel barrels but they are more $$$. For a dual or triple use option (hunting, long range shooting, competing) CF wrapped are a great option IF they fit your budget. If you’re going to compete and shoot thousands of rounds through it per year, a user changeable barrel is a big advantage.
So, bla bla bla right? You’ve heard all my rationale, now, I’ll actually make a recommendation. I’d go with a Springfield Waypoint 2020 or Seekins Havak PH3 in 6.5 PRC. Try to shoulder both and pick the one that appeals to you more. Put good glass and a suppressor on it if you can and go shoot the barrel out.
280 AI, 7 PRC, and 300 PRC are solid options too depending on your budget and if you hand load. I’ve been looking at reloading over the holidays and 6.5 PRC is widely available at a reasonable price, significantly less recoil than the bigger PRC’s, and very accurate in factory ammo. At the moment, 7 PRC is running 150 to 200 fps than box velocity in much of the factory ammo. More recoil than the 6.5 PRC but not as clear as a performance edge as it should be.
Hope this is useful, but if not at least entertaining! A Merry Christmas and Happy Holidays to you and yours.