timing chain & lifters

somehow i am in a questioning mood these days. Maybe it is because i pay 5k and more for a new 6.1 to rebuild and don't know what ruined my old one ( old.... 2010 engine, 30k mls ) ...

so, 2 questions: are stock chain and lifters fine or do i better spend a fistfull greens ( EUROS) in new HP stuff? Does those exist at all? Heard about lifters with way stronger needles in the rollers. Is that true?

Timing chain... brand, source, advice?
lifter... brand, source, advice?