>That said, do you have any stimulating onions on the Congo War?
No, I know very little about it.
>Or violent ballads?
Not really, Marty Robbins had his 'Gunfighter Ballads and Trail Songs' album which you might like. Quite a different style to Zevon but quite nice, particularly Big Iron and Mister Shorty.
You also might like Corb Lund's album 'Horse Soldier, Horse Soldier', particularly the song 'Student Visas'.
Some Neo-Nazi type bands such as Übermensch and Sleipnir might fit, the song 'In Anerkennung' by the former is one of my favourite German songs. Sabaton may also be an option.