I'd take a Browning A-Bolt II Ti or a Rem 700 Ti and give it a 23.75" Gaillard stainless super light barrel in 280 AI, that's what I am thinking about doing for the one all rifle
I just saw the Thread title and quickly replied earlier with the above, not for $1200 that's for sure,
for $1200
I'd find a used rifle in good shape and spend the better portion on optics or find a complete kit up for grabs,
so in that case a Browning A-Bolt II, or Rem 700, or Ruger M77 in SS in 280Rem and spend a few dollars at the G-Smith having the chamber reamed out to 280 AI
That ought to keep with in budget.
If not 7MM Rem Mag