Peckinpah, Sam American film director. SL offered him the opportunity to direct Giù la testa but he turn it down. Despite some rumors, they were friends rather than enemies. Though, SL claimed that Peckinpah's Wild Bunch wouldn't have been possible without the Dollars-trilogy.
Leone, Sergio Was born, lived and died in Rome (3.1.1929 - 30.4.1989). Son of silent film director Roberto Roberti (Vincenzo Leone) and actress Bice Waleran.Something like that? I think the very basic information is enough, everything else is said elsewhere.
The Kurosawa suggestion is a good one, too, but something of a tall order. I could use some help with specific examples that show styles, motifs, etc. the two directors used in common.
Actually, this is what Wallach says (113): I'll try to work something up to cover this and add it to the Wallach entry.
On Peacemaker's behalf, I added his entry on the historical General Huerta, part of the background for DYS.