Johnny Cash, Waylon Jennings, Willie Nelson and Kris Kristofferson made once a supergroup, called The Highwaymen. Their live version of "The Highwayman" is superb! (From that concert I love also "The City Of New Orleans")
You aare right about big speakers and crank it up. That's the only way to play Waylon. I especially love Waylon's "chicken pickin" on the guitar in this song. I just love the fact that he only plays what's needed. Never play 20 notes when one or two will do.
Also Toby Keith & Scott Emerick surprising Willie Nelson with...I'll Never Smoke Weed With Willie Again!! Also Willie & Merle Haggard do one called It's All Going to Pot!! Both great songs!!
In a country vein, you should check out "Long Haired Country Boy" by Charlie Daniels, and a forgotten classic, "Third Rate Romance" by Amazing Rhythm Aces.