First, thanks to everyone who replied to my original post. Your expertise and willingness is much appreciated.

Second, it appears the consensus is indeed a Colt LE 6920.

Third, a good red dot optic, I'm going with Aimpoint PRO.

Fourth, Grant's suggestion was to purchase a .22 rifle rather than a .22 upper (for inexpensive plinking fun), and after his suggestion and much more research on the forum I have decided to go with the S&W M&P 15-22.

Fifth, a few magazines for each rifle.

All of these items together cost right at $2000. Hooray! I am very satisfied and trying to order everything today. Once again, thanks for the great advice!

August