After months of denial, the two confessed to being involved in the murder of the 26-year-old mother after they were convicted for the crime several weeks ago.
Monye, a former Nigerian Olympic athletic, on Monday told the court that he was ashamed of his actions.
Henning was shot in Faerie Glen, in the east of Pretoria on November 8, 2011 shortly after dropping her son off at creche.
At the time, she had been involved in a custody battle with her estranged husband, Nico Henning.
He was arrested in December shortly after Gouws, who was his best friend, told the court that Henning had offered him R1 million to have his wife killed.
Gouws said he in turn offered Monye R50,000 to find killers for the job.
The killers, Gerhardus (Doepie) du Plessis and Willem (Tattoo or Pike) Pieterse, are serving 18-year jail sentences after pleading guilty to the murder.