Original: Robert Chartoff and Irwin Winkler in particular liked the script (which Stallone submitted to them after a casting), and planned on courting a star like Burt Reynolds or James Caan for the lead role.
Simplified: Robert Chartoff and Irwin Winkler both  liked the script (which Stallone submitted to them after a casting), and planned on having a star like Burt Reynolds or James Caan to play the lead character.