You can't go wrong with virtually anything from Marty Robbins's Gunfighter Ballads and Trail Songs, or Tom Russell's Cowboy Real and Songs from the West. I was always fond of Art Thieme's rendering of Cowboy's Barbara Allen too... and Dobie Bill. I guess that's more a gunfighter song than a cowboy song if you want to split horsehairs.

I'd reckon my absolute favorites, albeit not traditional, are Russell's The Sky Above, The Mud Below; Sonora's Death Row as recorded by Richard Shindell (yes, don't argue with me, it was on a relatively rare sampler which is available- drop me a line if you're interested) and Marty's recording of Utah Carroll.

And yes, there is at least one Sons of the Pioneers disc in print; Collectors Choice Music has it- my wife got it for me for Christmas this year.

jim