I have no idea which rifle might be the best.
What I do know, though you might be well aware of it, is that so many of these types have been available due to the price of NATO 7.62 or .308 ammo.
The lucky guys are those who had the gun bug more than several years ago when it was so much cheaper than in the last four years.
If you don't have access to this, good luck, unless you have really cheap components to reload or a really large ammo budget.
Brass gets banged up a good bit by some of these rifles during extraction.