The subject of the 783 came up on another board. A 'smith responded
that he was very UN-impressed with them, and had had to work on
a few of them. There's a reason they are so cheap, and cheaply made.
I have a RAR Predator in .204. The predators have a slightly heavier
barrel, and a different colored stock than the Ruger American you
are considering. The bolt wasn't machined as smooth as most, and
you could hear/feel the difference when working it. A little Flitz and
"0000" steel wool worked wonders. The tupperware stock was
replaced with a Boyd's (hardware comes with pillars). It is now a joy
to own.
The 700's have so much after-market support, it's hard to say the
ADL is not the best choice. But it also comes with a flimsy stock. Be
prepared to relieve the barrel channel on one side or the other. If
it were me, I'd be shopping at Boyd's site as soon as getting the
rifle.
As for caliber choice, you have made the right one. The round itself
is known for accuracy and the recoil is such that one can shoot it
all day without becoming recoil shy. I cannot shoot my 7mm08 all
day and say that, but can say so with my .243.