For a pre-built AR-10, I'd go with a
Lewis Machine & Tool, or
NoveskeLMT is one of the real manufacturers that the smaller companies have build their parts.
Continental Machine & Tool is one of the others (civilian brand is Stag Arms)
For myself,
Mega Ma-Ten upper/lower,
JP Bolt,
Krieger barrel,
Geissele trigger group,
Armalite lower parts kit,
Tango Down grip,
Magpul PRS stock.
Probably in 6.5x47 Lapua
But..
Which way to spend a pile of money first?
AR-10 variant + optics + reloading dies + 1000 rounds of Lapua brass + powder/primer/bullets + magazines + slings, etc etc
-or-
Classical Bavarian-style hunting rifle,
Mauser style action,
classical custom wood stock,
S&B optics,
6.5x55 SE,
Bavarian drop-comb buttstock,
Steyr-Mannlicher foreend (or not..?)
-or-
Night vision mount for my AICS stocked 300 WSM + detachable night vision module in front of the scope + Suppressor.
Personally, I'm leaning towards the NV and suppressor. Just as soon as the Montana Fish & Game figures out that suppressors have been legal for predator (coyote, etc) shooting since November. Their headquarters hasn't figured it out yet, so... until they get their facts straight, no sense arguing with them.