Sahid Sule, who has no permanent address, and Nicholas Allon-McVytie of London were given automatic life sentences by a judge at the Old Bailey, The Daily Mirror reported. The two men, both 23, must serve at least 28 years before release.
The victim, Michael Ofori, 35, was killed while he was sitting in his car. He was a cousin of Paul Sackey, a former member of the England rugby team, who said the death was "a real struggle."
The man who allegedly carried out the hit and another participant face a new trial after a jury was unable to agree on the verdict.
Investigators said they believe Ofori, a personal trainer, was mistaken for a 24-year-old gang member after a series of shootings in a feud between gang members, the BBC said.
"This was a deliberate execution carried out in a public street in the presence of the victim's wife," Judge Peter Thornton said. "You have brutally taken the life of a man loved by his friends and relatives."