You can't go wrong with the 18.0" Bush/Scout M1A.
When I asked the same question many years ago, everyone told me get
the standard... I thanked them for their opinions and purchased a Scout.
I now own a 16.25", two 18.0" and three standard length configurations.
The 18.0" is my personal favorite.
Their are plenty of stocks to choose from, a tight fitting USGI synthetic
with a reinforced fore end is really nice. I prefer a pistol grip and like the
SAGE EBR, I'll also have a Blackfeather RS soon and it looks like a winner.
Sold my AR-15 after I purchased my Scout...
Sold my AR-10 to fund a custom built SEI M14...